#include<iostream>
using namespace std;
int main() {
	int v[10000000];int ti[10000000];
   int high[10000000];
	bool block[10000000];
    int n, t;
    cin >> n >> t;
    for (int i = 0; i < n; i++) {
        cin >> v[i];
		cin >> ti[i]; 
		block[i] = 0; 
		high[i] = 0;
    } int m;
    for (int j = 0; j < t; j++) {
    	for (m = 0; m < n; m++) {
    		if (!block[m] && ti[m] <= j)
    		    block[m] = 1;
    		if (block[m])
    		    high[m] += v[m];
		}
	}
	int highest = high[0], highs =  0;
	for (int o = 0; o < n; o++)
	    if (high[o] > highest) {
	    	highest = high[o];
	    	highs = o;
		}
	cout << highs + 1;
    return 0;
}