#include<stdio.h>
int v[1003], w[1003];
int main()
{
	int n, W;
	scanf("%d %d", &n, &W);
	int i;
	for (i = 0; i < n; i++)
		scanf("%d %d", &v[i], &w[i]);
	int ans = -1;
	for (i = 0; i < n; i++)
		if (w[i] <= W && ans < v[i])
			ans = v[i];
	printf("%d\n", ans);
	return 0;
}