#define _USE_MATH_DEFINES
#include  <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <string>
#include<math.h>
#include<iomanip>
#include<stdio.h>
#include <stdlib.h>
#include<stdio.h>
#include <queue>
#include<map>
#include <sstream>
#include<set>
#include<stack>
#include<time.h>
#include <sys/types.h>
#include <tuple>


typedef long long int ll;
//#include<bits/stdc++.h>


using namespace std;



int main()
{

    int Q;
    Q = 1;
    //cin >> Q;


   
    while (Q--) {
        int n, w;
        cin >> n >> w;

        int ans = -1;
        int t = -1;
        for (int i = 0; i < n; i++) {
            int a, b;
            cin >> a >> b;
            if (b <= w) {
                if (ans < a) {
                    ans = a;
                    
                }
            }
        }
        cout << ans << endl;
        
        



    }

    return 0;
}