#include <iostream>
#include <algorithm>
using namespace std;

int n, W;
int v[1000], w[10000];

int main() {
	cin >> n >> W;
	
	int ans = -1;
	for (int i = 0; i < n; i++) {
		cin >> v[i] >> w[i];
		if (w[i] <= W) {
			ans = max(v[i], ans);
		}
	}
	
	cout << ans << endl;
	return 0;
}