#include <bits/stdc++.h>
using namespace std;
struct a
{
    int id,way;
}x[100010];
bool cmp(a a1,a a2)
{
    if(a1.way!=a2.way)return a1.way>a2.way;
    return a1.id<a2.id;
}
int main()
{
    int n,T;
    cin>>n>>T;
    for(int i=1;i<=n;i++)
    {
        int v,t;
        cin>>v>>t;
        x[i].id=i;
        x[i].way=(T-t)*v;
    }
    sort(x+1,x+n+1,cmp);
    cout<<x[1].id;
    return 0;
}