#include <iostream>
#include <fstream>

using namespace std;

int main()
{
    ifstream in("energii.in");
    ofstream out("energii.out");
    int G, W, EGi, CGi, Cmin;
    in>>G;
    in>>W;
    for(int i = 0; i < G; i++)
    {
        in>>EGi; in>>CGi;
        if(EGi >= W)
            Cmin = CGi;
    }
    out<<Cmin;
}