#include <bits/stdc++.h>
using namespace std;

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int N,W; cin >> N >> W;
    int answer = -1;
    for(int i=0; i<N; i++){
        int v,w; cin >> v >> w;
        if(w <= W) answer = max(v,answer);
    }
    cout << answer << endl;
}