POJ 3664

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>

using namespace std;
const int N=50100;

struct COW{
int f,s,d;
}cows
;

bool cmp1(COW a,COW b){
if(a.f>b.f) return true;
return false;
}

bool cmp2(COW a,COW b){
if(a.s>b.s) return true;
return false;
}

int n,k;

int main(){
while(scanf("%d%d",&n,&k)!=EOF){
for(int i=0;i<n;i++){
scanf("%d%d",&cows[i].f,&cows[i].s);
cows[i].d=i+1;
}
sort(cows,cows+n,cmp1);
sort(cows,cows+k,cmp2);
printf("%d\n",cows[0].d);
}
return 0;
}