1 #include <cstdio>
2 #include <iostream>
3 #include <algorithm>
4 using namespace std;
5 long long sz1[600010],sz2[600010],x[600010],y[600010],s,num,sumx,sumy,d;
6 int n,cnt1[600010],cnt2[600010],rank1[600010],rank2[600010],d1[600010],d2[600010];
7 bool cmpx(int a,int b) { return x[a]<x[b]; }
8 bool cmpy(int a,int b) { return y[a]<y[b]; }
9 void insert1(int x,int y)
10 {
11 for (;x<=n;x+=x&-x) sz1[x]+=y,cnt1[x]++;
12 }
13 void insert2(int x,int y)
14 {
15 for (;x<=n;x+=x&-x) sz2[x]+=y,cnt2[x]++;
16 }
17 long long getsum1(int x,long long &y)
18 {
19 long long s=0;
20 for (;x;x-=x&-x) s+=sz1[x],y+=cnt1[x];
21 return s;
22 }
23 long long getsum2(int x,long long &y)
24 {
25 long long s=0;
26 for (;x;x-=x&-x) s+=sz2[x],y+=cnt2[x];
27 return s;
28 }
29 long long query1(int l,int r,long long &num)
30 {
31 long long tot=0,s=getsum1(r,num)-getsum1(l-1,tot);
32 num-=tot;
33 return s;
34 }
35 long long query2(int l,int r,long long &num)
36 {
37 long long tot=0,s=getsum2(r,num)-getsum2(l-1,tot);
38 num-=tot;
39 return s;
40 }
41 int main()
42 {
43 scanf("%d%lld",&n,&d);
44 for (int i=1;i<=n;i++)
45 {
46 scanf("%lld%lld",&x[i],&y[i]);
47 d1[i]=d2[i]=i;
48 }
49 sort(d1+1,d1+n+1,cmpx);
50 sort(d2+1,d2+n+1,cmpy);
51 for (int i=1;i<=n;i++) rank1[d1[i]]=i,rank2[d2[i]]=i;
52 for (int i=1;i<=n;i++)
53 {
54 num=0,sumx=query1(1,rank1[i],num),s+=num*x[i]-sumx;
55 num=0,sumx=query1(rank1[i],n,num),s+=sumx-num*x[i];
56 num=0,sumy=query2(1,rank2[i],num),s+=num*y[i]-sumy;
57 num=0,sumy=query2(rank2[i],n,num),s+=sumy-num*y[i];
58 if (s>d)
59 {
60 printf("%d",i);
61 return 0;
62 }
63 insert1(rank1[i],x[i]),insert2(rank2[i],y[i]);
64 }
65 printf("-1");
66 return 0;
67 }
