1 #include<bits/stdc++.h>
2 using namespace std;
3 const int N=30010;
4 int n,sz,ch[N][2],fl[N],que[N],head,tail,vis[N],hd[N],o,dfn[N],idx,low[N],fg,del[N];
5 struct Edge{int v,nt;}E[N<<1];
6 char s[N];
7 void adde(int u,int v){
8 if(u==v)fg=1;
9 E[o]=(Edge){v,hd[u]};hd[u]=o++;
10 }
11 void get_fl(){
12 for(int i=0;i<2;i++)if(ch[0][i]){
13 que[++tail]=ch[0][i];
14 if(!vis[ch[0][i]])adde(0,ch[0][i]);
15 }else {fg=1;return;}
16 while(head<tail){
17 int u=que[++head];
18 for(int i=0;i<2;i++){
19 int&v=ch[u][i];
20 if(!v){
21 v=ch[fl[u]][i];
22 if(!vis[v])adde(u,v);
23 continue;
24 }
25 fl[v]=ch[fl[u]][i];
26 vis[v]|=vis[fl[v]];
27 if(!vis[v])adde(u,v);
28 que[++tail]=v;
29 }
30 }
31 }
32 void tarjan(int u){
33 if(fg)return ;
34 que[++head]=u;
35 dfn[u]=low[u]=++idx;
36 for(int i=hd[u];~i;i=E[i].nt){
37 int v=E[i].v;
38 if(!dfn[v])tarjan(v),low[u]=min(low[u],low[v]);
39 else if(!del[v])low[u]=min(low[u],dfn[v]);
40 }
41 if(dfn[u]==low[u]){
42 int cnt=0,v;
43 do{
44 cnt++;
45 del[v=que[head--]]=1;
46 }while(v!=u);
47 if(cnt > 1)fg=1;
48 }
49 }
50 int main(){
51 // freopen("bzoj2938.in","r",stdin);
52 // freopen("bzoj2938.out","w",stdout);
53 memset(hd,-1,sizeof(hd));
54 scanf("%d",&n);
55 for(int i=1;i<=n;i++){
56 scanf("%s",s+1);
57 int len=strlen(s+1),u=0;
58 for(int j=1;j<=len;j++){
59 if(!ch[u][s[j]-'0'])ch[u][s[j]-'0']=++sz;
60 u=ch[u][s[j]-'0'];
61 }
62 vis[u]=1;
63 }
64 get_fl();
65 head=0;tarjan(0);
66 if(fg)puts("TAK");else puts("NIE");
67 return 0;
68 }
bzoj2938
