1 #include<algorithm>
2 #include<iostream>
3 #include<cstdlib>
4 #include<cstring>
5 #include<cstdio>
6 #include<string>
7 #include<cmath>
8 #include<ctime>
9 #include<queue>
10 #include<stack>
11 #include<map>
12 #include<set>
13 #define rre(i,r,l) for(int i=(r);i>=(l);i--)
14 #define re(i,l,r) for(int i=(l);i<=(r);i++)
15 #define Clear(a,b) memset(a,b,sizeof(a))
16 #define inout(x) printf("%d",(x))
17 #define douin(x) scanf("%lf",&x)
18 #define strin(x) scanf("%s",(x))
19 #define LLin(x) scanf("%lld",&x)
20 #define op operator
21 #define CSC main
22 typedef unsigned long long ULL;
23 typedef const int cint;
24 typedef long long LL;
25 using namespace std;
26 void inin(int &ret)
27 {
28 ret=0;int f=0;char ch=getchar();
29 while(ch<'0'||ch>'9'){if(ch=='-')f=1;ch=getchar();}
30 while(ch>='0'&&ch<='9')ret*=10,ret+=ch-'0',ch=getchar();
31 ret=f?-ret:ret;
32 }
33 namespace kruskal//codevs1078
34 {
35 struct bian
36 {
37 int u,v,w;
38 bool op < (const bian &rhs)const {return w<rhs.w;}
39 }bi[10010];
40 int fa[111],n,ed;
41 int find(int x){return x==fa[x]?x:fa[x]=find(fa[x]);}
42 int kruskal()
43 {
44 re(i,1,n)fa[i]=i;
45 sort(bi+1,bi+ed+1);
46 int tot=0,ret=0;
47 re(i,1,ed)
48 {
49 int q=find(bi[i].u),w=find(bi[i].v);
50 if(q!=w)fa[q]=w,tot++,ret+=bi[i].w;
51 if(tot==n-1)break;
52 }
53 return ret;
54 }
55 void solve()
56 {
57 inin(n);
58 re(i,1,n)re(j,1,n)
59 {
60 int x;inin(x);
61 if(j>i&&x)ed++,bi[ed].u=i,bi[ed].v=j,bi[ed].w=x;
62 }
63 printf("%d",kruskal());
64 }
65 }
66 namespace prim//codevs1078
67 {
68 int head[111],next[20020],zhi[20020],w[20020],dis[20020],ed;
69 void add(int a,int b,int c)
70 {
71 next[++ed]=head[a],head[a]=ed,zhi[ed]=b,w[ed]=c;
72 next[++ed]=head[b],head[b]=ed,zhi[ed]=a,w[ed]=c;
73 }
74 struct wocao
75 {
76 int id,w;
77 wocao(int id=0,int w=0):id(id),w(w){}
78 bool op < (const wocao &rhs)const {return w>rhs.w;}
79 };
80 priority_queue<wocao>h;
81 bool bo[111];
82 int prim()
83 {
84 int sum=0;
85 Clear(dis,127);dis[1]=0;
86 h.push(wocao(1,0));
87 while(!h.empty())
88 {
89 int x=h.top().id;h.pop();
90 if(bo[x])continue;
91 bo[x]=1;sum+=dis[x];
92 for(int i=head[x];i;i=next[i])if(!bo[zhi[i]]&&dis[zhi[i]]>w[i])
93 dis[zhi[i]]=w[i],h.push(wocao(zhi[i],dis[zhi[i]]));
94 }
95 return sum;
96 }
97 int n;
98 void solve()
99 {
100 inin(n);
101 re(i,1,n)re(j,1,n)
102 {
103 int x;inin(x);
104 if(j>i&&x)add(i,j,x);
105 }
106 printf("%d",prim());
107 }
108 }
109 namespace floyd//codevs1077
110 {
111 const int inf=2147483647>>1;
112 int a[111][111],n,m,q,w;
113 void floyd()
114 {
115 re(i,1,n)re(j,1,n)re(k,1,n)
116 a[j][k]=min(a[j][k],a[j][i]+a[i][k]);
117 }
118 void solve()
119 {
120 inin(n);
121 re(i,1,n)re(j,1,n)inin(a[i][j]);
122 floyd();
123 inin(m);
124 re(i,1,m)
125 {
126 inin(q),inin(w);
127 printf("%d\n",a[q][w]);
128 }
129 }
130 }
131 namespace dijkstra//codevs1077
132 {
133 int head[111],next[20020],zhi[20020],w[20020],dis[111][111],ed;
134 int n,m;
135 void add(int a,int b,int c)
136 {
137 next[++ed]=head[a],head[a]=ed,zhi[ed]=b,w[ed]=c;
138 next[++ed]=head[b],head[b]=ed,zhi[ed]=a,w[ed]=c;
139 }
140 struct wocao
141 {
142 int id,w;
143 wocao(int id=0,int w=0):id(id),w(w){}
144 bool op < (const wocao &rhs)const {return w>rhs.w;}
145 };
146 priority_queue<wocao>h;
147 bool bo[111];
148 void dijkstra(int s)
149 {
150 Clear(dis[s],127);Clear(bo,0);
151 dis[s][s]=0;
152 h.push(wocao(s,0));
153 while(!h.empty())
154 {
155 int x=h.top().id;h.pop();
156 if(bo[x])continue;
157 bo[x]=1;
158 for(int i=head[x];i;i=next[i])
159 if(!bo[zhi[i]]&&dis[s][zhi[i]]>dis[s][x]+w[i])
160 {
161 dis[s][zhi[i]]=dis[s][x]+w[i];
162 h.push(wocao(zhi[i],dis[s][zhi[i]]));
163 }
164 }
165 }
166 void solve()
167 {
168 inin(n);
169 re(i,1,n)re(j,1,n)
170 {
171 int x;inin(x);
172 if(j>i&&x)add(i,j,x);
173 }
174 re(i,1,n)dijkstra(i);
175 inin(m);
176 re(i,1,m)
177 {
178 int a,b;inin(a),inin(b);
179 printf("%d\n",dis[a][b]);
180 }
181 }
182 }
183 namespace spfa//codevs1077
184 {
185 int head[111],next[20020],zhi[20020],w[20020],ed,dis[111][111];
186 int n,m;
187 void add(int a,int b,int c)
188 {
189 next[++ed]=head[a],head[a]=ed,zhi[ed]=b,w[ed]=c;
190 next[++ed]=head[b],head[b]=ed,zhi[ed]=a,w[ed]=c;
191 }
192 queue<int>h;
193 bool bo[111];
194 void spfa(int s)
195 {
196 Clear(dis[s],127);dis[s][s]=0;
197 h.push(s);
198 while(!h.empty())
199 {
200 int x=h.front();h.pop();bo[x]=0;
201 for(int i=head[x];i;i=next[i])
202 if(dis[s][zhi[i]]>dis[s][x]+w[i])
203 {
204 dis[s][zhi[i]]=dis[s][x]+w[i];
205 if(!bo[zhi[i]])bo[zhi[i]]=1,h.push(zhi[i]);
206 }
207 }
208 }
209 void solve()
210 {
211 inin(n);
212 re(i,1,n)re(j,1,n)
213 {
214 int x;inin(x);
215 if(j>i&&x)add(i,j,x);
216 }
217 re(i,1,n)spfa(i);
218 inin(m);
219 re(i,1,m)
220 {
221 int a,b;inin(a),inin(b);
222 printf("%d\n",dis[a][b]);
223 }
224 }
225 }
226 namespace scc//codevs2822
227 {
228 int head[100010],next[200020],zhi[200020],ed;
229 int dfn[100010],low[100010],sccno[100010],num[100010],tot,sum;
230 int sta[100010],top,n,m;
231 void add(int a,int b)
232 {
233 next[++ed]=head[a],head[a]=ed,zhi[ed]=b;
234 }
235 void tarjan(int x)
236 {
237 dfn[x]=low[x]=++tot;
238 sta[++top]=x;
239 for(int i=head[x];i;i=next[i])
240 {
241 int v=zhi[i];
242 if(!dfn[v])tarjan(v),low[x]=min(low[x],low[v]);
243 else if(!sccno[v])low[x]=min(low[x],dfn[v]);
244 }
245 if(low[x]==dfn[x])
246 {
247 sum++;
248 while(1)
249 {
250 int xx=sta[top--];
251 sccno[xx]=sum,num[sum]++;
252 if(xx==x)break;
253 }
254 }
255 }
256 void find_scc()
257 {
258 re(i,1,n)if(!dfn[i])tarjan(i);
259 }
260 int chu[100010],ans;
261 void rebuild()
262 {
263 re(i,1,n)for(int j=head[i];j;j=next[j])
264 if(sccno[i]!=sccno[zhi[j]])chu[sccno[i]]++;
265 int bo=-1;
266 re(i,1,sum)if(num[i]>1)
267 {
268 ans++;
269 if(!chu[i])
270 {
271 if(!bo)continue;
272 else if(bo==-1)bo=i;
273 else bo=0;
274 }
275 }
276 printf("%d\n",ans);
277 if(bo>0)
278 re(i,1,n)if(sccno[i]==bo)printf("%d ",i);else ;
279 else cout<<-1;
280 }
281 void solve()
282 {
283 inin(n),inin(m);
284 re(i,1,m)
285 {
286 int q,w;inin(q),inin(w);
287 add(q,w);
288 }
289 find_scc();
290 rebuild();
291 }
292 }
293 namespace bcc
294 {
295 int dfn[100010],cut[100010],bccno[100010],tot,sum;
296 int head[50050],next[100010],zhi[100010],ed;
297 void add(int a,int b)
298 {
299 next[++ed]=head[a],head[a]=ed,zhi[ed]=b;
300 next[++ed]=head[b],head[b]=ed,zhi[ed]=a;
301 }
302 struct bian
303 {
304 int u,v;
305 bian(int u=0,int v=0):u(u),v(v){}
306 };
307 vector<int>bcc[100010];
308 stack<bian>s;
309 int dfs(int u,int fa)
310 {
311 int lowu=dfn[u]=++tot;
312 int ne=0;
313 for(int i=head[u];i;i=next[i])
314 {
315 int v=zhi[i];
316 bian e(u,v);
317 if(!dfn[v])
318 {
319 s.push(e),ne++;
320 int lowv=dfs(v,u);
321 lowu=min(lowu,lowv);
322 if(lowv>=dfn[u]);
323 {
324 cut[u]=1;
325 sum++;bcc[sum].clear();
326 while(1)
327 {
328 bian x=s.top();s.pop();
329 if(bccno[x.u]!=sum){bcc[sum].push_back(x.u);bccno[x.u]=sum;}
330 if(bccno[x.v]!=sum){bcc[sum].push_back(x.v);bccno[x.v]=sum;}
331 if(x.u==u&&x.v==v)break;
332 }
333 }
334 }
335 else if(dfn[v]<dfn[u]&&v!=fa)
336 {
337 s.push(e);
338 lowu=min(lowu,dfn[v]);
339 }
340 }
341 if(!fa&&ne==1)cut[u]=0;
342 return lowu;
343 }
344 void solve()
345 {
346 int n,m;
347 inin(n),inin(m);
348 re(i,1,m)
349 {
350 int q,w;inin(q),inin(w);
351 add(q,w);
352 }
353 re(i,1,n)dfs(i,0);
354 printf("%d",sum);
355 }
356 }
357 namespace dinic//codevs1993
358 {
359 const int inf=2147483647;
360 int head[222],next[444],zhi[444],cap[444],ed=1,cur[222];
361 int n,m;
362 void add(int a,int b,int c)
363 {
364 next[++ed]=head[a],head[a]=ed,zhi[ed]=b,cap[ed]=c;
365 next[++ed]=head[b],head[b]=ed,zhi[ed]=a,cap[ed]=0;
366 }
367 queue<int>h;int dis[222];
368 bool bfs(int s,int t)
369 {
370 Clear(dis,0);
371 dis[s]=1;h.push(s);
372 while(!h.empty())
373 {
374 int x=h.front();h.pop();
375 for(int i=head[x];i;i=next[i])
376 if(cap[i]&&!dis[zhi[i]])
377 {
378 dis[zhi[i]]=dis[x]+1;
379 h.push(zhi[i]);
380 }
381 }
382 return dis[t];
383 }
384 int dfs(int x,int Max,int t)
385 {
386 if(x==t||!Max)return Max;
387 int temp,ret=0;
388 for(int &i=cur[x];i;i=next[i])
389 if(cap[i]&&dis[zhi[i]]==dis[x]+1)
390 {
391 temp=dfs(zhi[i],min(Max,cap[i]),t);
392 ret+=temp,Max-=temp;
393 cap[i]-=temp,cap[i^1]+=temp;
394 if(!Max)return ret;
395 }
396 if(!ret)dis[x]=-1;
397 return ret;
398 }
399 int dinic(int s,int t)
400 {
401 int ret=0;
402 while(bfs(s,t))
403 {
404 re(i,1,n)cur[i]=head[i];
405 ret+=dfs(s,inf,t);
406 }
407 return ret;
408 }
409 void solve()
410 {
411 inin(m),inin(n);
412 re(i,1,m)
413 {
414 int q,w,e;
415 inin(q),inin(w),inin(e);
416 add(q,w,e);
417 }
418 printf("%d",dinic(1,n));
419 }
420 }
421 namespace mcf//codevs1227
422 {
423 const int inf=2147483647;
424 int head[6060],next[1000020],zhi[1000020],cap[1000020],w[1000020],ed=1;
425 void add(int a,int b,int c,int d)
426 {
427 next[++ed]=head[a],head[a]=ed,zhi[ed]=b,cap[ed]=c,w[ed]=d;
428 next[++ed]=head[b],head[b]=ed,zhi[ed]=a,cap[ed]=0,w[ed]=-d;
429 }
430 int n,k,dis[6060],pre[6060];
431 queue<int>h;bool bo[6060];
432 bool spfa(int s,int t)
433 {
434 Clear(dis,-1);
435 dis[s]=0,h.push(s);
436 while(!h.empty())
437 {
438 int x=h.front();h.pop();bo[x]=0;
439 for(int i=head[x];i;i=next[i])
440 {
441 if(!cap[i]||dis[zhi[i]]>=dis[x]+w[i])continue;
442 dis[zhi[i]]=dis[x]+w[i];
443 pre[zhi[i]]=i;
444 if(!bo[zhi[i]])h.push(zhi[i]),bo[zhi[i]]=1;
445 }
446 }
447 return dis[t]!=-1;
448 }
449 int mcf(int s,int t)
450 {
451 int ret=0,Min;
452 while(spfa(s,t))
453 {
454 Min=inf;
455 for(int i=t;pre[i];i=zhi[pre[i]^1])
456 Min=min(Min,cap[pre[i]]);
457 for(int i=t;pre[i];i=zhi[pre[i]^1])
458 cap[pre[i]]-=Min,cap[pre[i]^1]+=Min;
459 ret+=Min*dis[t];
460 }
461 return ret;
462 }
463 void solve()
464 {
465 inin(n),inin(k);int s=6001,t=6002;
466 re(i,1,n)re(j,1,n)
467 {
468 int x;inin(x);
469 int ss=(i-1)*n+j,tt=ss+n*n;
470 add(ss,tt,1,x);
471 add(ss,tt,k,0);
472 if(i<n)add(tt,ss+n,k,0);
473 if(j<n)add(tt,ss+1,k,0);
474 }
475 add(s,1,k,0);
476 add(n*n*2,t,k,0);
477 printf("%d",mcf(s,t));
478 }
479 }
480 namespace hungary//codevs1022
481 {
482 int head[10010],next[40040],zhi[40040],pre[10010],ed,bo[10010];
483 void add(int a,int b)
484 {
485 next[++ed]=head[a],head[a]=ed,zhi[ed]=b;
486 next[++ed]=head[b],head[b]=ed,zhi[ed]=a;
487 }
488 int n,m,k,a[111][111];
489 bool find(int x,int t)
490 {
491 for(int i=head[x];i;i=next[i])if(bo[zhi[i]]!=t)
492 {
493 bo[zhi[i]]=t;
494 if(!pre[zhi[i]]||find(pre[zhi[i]],t))
495 {
496 pre[zhi[i]]=x;
497 return 1;
498 }
499 }
500 return 0;
501 }
502 void solve()
503 {
504 inin(n),inin(m),inin(k);
505 re(i,1,k)
506 {
507 int x,y;
508 inin(x),inin(y);
509 a[x][y]=1;
510 }
511 re(i,1,n)re(j,1,m)if(!a[i][j])
512 {
513 if(i<n&&!a[i+1][j])add((i-1)*n+j,(i*n+j));
514 if(j<m&&!a[i][j+1])add((i-1)*n+j,(i-1)*n+j+1);
515 }
516 int ans=0;
517 re(i,1,n)re(j,1,m)if(!a[i][j])if(find((i-1)*n+j,(i-1)*n+j))ans++;
518 cout<<ans/2;
519 }
520 }
521 namespace point_divide
522 {
523 int n;
524 int head[20020],next[40040],zhi[40040],ed,si[20020],w[20020],v[40040];
525 int root,sum,ans,bo[20020];
526 void add(int a,int b,int c)
527 {
528 next[++ed]=head[a],head[a]=ed,zhi[ed]=b,v[ed]=c;
529 next[++ed]=head[b],head[b]=ed,zhi[ed]=a,v[ed]=c;
530 }
531 int gcd(int a,int b)
532 {
533 int c;
534 while(a%b)c=a%b,a=b,b=c;
535 return b;
536 }
537 void getroot(int x,int fa)
538 {
539 si[x]=1;w[x]=0;
540 for(int i=head[x];i;i=next[i])if(!bo[zhi[i]]&&zhi[i]!=fa)
541 {
542 getroot(zhi[i],x);
543 si[x]+=si[zhi[i]];
544 w[x]=max(w[x],si[zhi[i]]);
545 }
546 w[x]=max(w[x],sum-si[x]);
547 if(w[x]<w[root])root=x;
548 }
549 int dis[20020],shu[3];
550 void getans(int x,int fa)
551 {
552 shu[dis[x]]++;
553 for(int i=head[x];i;i=next[i])
554 if(zhi[i]!=fa&&!bo[zhi[i]])
555 {
556 dis[zhi[i]]=(dis[x]+v[i])%3;
557 getans(zhi[i],x);
558 }
559 }
560 int js(int x,int temp)
561 {
562 shu[0]=shu[1]=shu[2]=0;
563 dis[x]=temp;getans(x,0);
564 return shu[1]*shu[2]*2+shu[0]*shu[0];
565 }
566 void solve(int x)
567 {
568 ans+=js(x,0);
569 bo[x]=1;
570 for(int i=head[x];i;i=next[i])if(!bo[zhi[i]])
571 {
572 ans-=js(zhi[i],v[i]);
573 root=0;sum=si[zhi[i]];
574 getroot(zhi[i],0);
575 solve(root);
576 }
577 }
578 void solve()
579 {
580 inin(n);
581 re(i,2,n)
582 {
583 int q,w,e;
584 inin(q),inin(w),inin(e);
585 add(q,w,e%3);
586 }
587 sum=w[0]=n;
588 getroot(1,0);
589 solve(root);
590 int wocao=gcd(ans,n*n);
591 printf("%d/%d",ans/wocao,n*n/wocao);
592 }
593 }
594 namespace km
595 {
596 int n,head[10010],next[100010],zhi[100010],w[100010];
597 int lx[10010],ly[10010],pre[10010],s[10010],t[10010];
598 bool find(int x,int T)
599 {
600 s[x]=T;
601 for(int i=head[x];i;i=next[i])
602 if(lx[x]+ly[zhi[i]]==w[i]&&t[zhi[i]]!=T)
603 {
604 t[zhi[i]]=T;
605 if(!pre[zhi[i]]||find(pre[zhi[i]],T))
606 {
607 pre[zhi[i]]=x;
608 return 1;
609 }
610 }
611 return 0;
612 }
613 void maintain(int T)
614 {
615 int a=1<<30;
616 re(i,1,n)if(s[i]==T)
617 for(int j=head[i];j;j=next[j])if(t[zhi[j]]!=T)
618 a=min(a,lx[i]+ly[zhi[j]]-w[j]);
619 re(i,1,n)
620 {
621 if(s[i]==T)lx[i]-=a;
622 if(t[i]==T)ly[i]+=a;
623 }
624 }
625 void km()
626 {
627 re(i,1,n)
628 {
629 pre[i]=lx[i]=ly[i]=0;
630 for(int j=head[i];j;j=next[j])
631 lx[i]=max(lx[i],w[j]);
632 }
633 for(int i=1,T=1;i<=n;i++)for(;;)
634 if(find(i,++T))break;else maintain(T);
635 }
636 }
637 namespace twosat
638 {
639 int n,head[200020],next[400040],zhi[400040],ed,s[400040],c;
640 bool bo[200020];
641 bool dfs(int x)
642 {
643 if(bo[x^1])return 0;
644 else if(bo[x])return 1;
645 bo[x]=1,s[c++]=x;
646 for(int i=head[x];i;i=next[i])
647 if(!dfs(zhi[i]))return 0;
648 return 1;
649 }
650 void add(int a,int b)
651 {
652 next[++ed]=head[a],head[a]=ed,zhi[ed]=b;
653 }
654 void add(int x,int vx,int y,int vy)
655 {
656 x=x*2+vx,y=y*2+vy;
657 add(x^1,y),add(y^1,x);
658 }
659 bool solve()
660 {
661 for(int i=0;i<n<<1;i+=2)if(!bo[i]&&!bo[i+1])
662 {
663 c=0;
664 if(!dfs(i))
665 {
666 while(c>0)bo[s[--c]]=0;
667 if(!dfs(i+1))return 0;
668 }
669 }
670 return 1;
671 }
672 void in()
673 {
674 inin(n);
675 re(i,0,n<<1)head[i]=0;
676 Clear(bo,0);
677 }
678 }
679 namespace zhuliu
680 {
681 const int inf=2147483647;
682 struct bian
683 {
684 int a,b,v;
685 bian(int a=0,int b=0,int v=0):a(a),b(b),v(v){}
686 };
687 int n,m;
688 bian bi[40040];
689 int bo[1010],pre[1010],in[1010],id[1010];
690 void init(int x,int y){n=x;m=y;}
691 void add(int a,int b,int c,int i){bi[i].a=a,bi[i].b=b,bi[i].v=c;}
692 int solve(int root)
693 {
694 int ret=0;
695 while(1)
696 {
697 re(i,1,n)in[i]=inf;
698 re(i,1,m)
699 {
700 int u=bi[i].a,v=bi[i].b;
701 if(bi[i].v<in[v]&&u!=v)in[v]=bi[i].v,pre[v]=u;
702 }
703 re(i,1,n)if(i!=root&&in[i]==inf)return -1;
704 int sum=0;
705 Clear(id,0);
706 Clear(bo,0);
707 in[root]=0;
708 re(i,1,n)
709 {
710 ret+=in[i];
711 int v=i;
712 while(bo[v]!=i&&!id[v]&&v!=root)bo[v]=i,v=pre[v];
713 if(v!=root&&!id[v])
714 {
715 sum++;
716 for(int u=pre[v];u!=v;u=pre[u])
717 id[u]=sum;
718 id[v]=sum;
719 }
720 }
721 if(!sum)break;
722 re(i,1,n)if(!id[i])id[i]=++sum;
723 re(i,1,m)
724 {
725 int v=bi[i].b;
726 bi[i].a=id[bi[i].a];
727 bi[i].b=id[bi[i].b];
728 if(bi[i].a!=bi[i].b)bi[i].v-=in[v];
729 }
730 n=sum;
731 root=id[root];
732 }
733 return ret;
734 }
735 }
736 int main()
737 {
738 return 0;
739 }
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