#include <iostream>
#include <fstream>
#include <cmath>

using namespace std;

int main()

{
	ifstream fin("energii.in");
	ofstream fout("energii.out");
	int t, e, a[1002], b[1002]; double c[1002];
	fin >> t;
	fin >> e;
	for (int i = 1; i <= t; i++)
	{
		fin >> a[i] >> b[i];
		c[i] = (b[i]*1.00)/ a[i];	
	}	
	bool u;
	do {
		u = false;
		for(int j = 1; j <= t; j++)
			if(c[j] < c[j-1])
			{
				swap(c[j],c[j-1]);
				swap(a[j],a[j-1]);
				swap(b[j],b[j-1]);
				u = true;
			}
	} while (u);
	int energie = 0, suma = 0;
	int i = 1;
	while (energie < e && i <= t)
	{
		energie = a[i];
		suma = b[i];
		i++;
	}
	if (energie >= e) 
		fout << suma;
	else fout << "-1";
	return 0;
}