#include <bits/stdc++.h>
using namespace std;
long long n, T, v, t, ans, ansid;
int main() {
    cin >> n >> T;
    for(int i = 1; i <= n; i++) {
        cin >> v >> t;
        if((T - t) * v > ans) ans = (T - t) * v, ansid = i;
    }
    cout << ansid;
    return 0;
}

啊这