#include <iostream>
#include <vector>
#include <iomanip>
#include <algorithm>
#include <map>
#include <cmath>
#include <bitset>
#include <string>
#include <queue>
#include <stack>
#include <set>
#include <tuple>
#include <atcoder/all>
#include <sstream> // std::stringstream
#include <regex>
#include <fstream>
using namespace atcoder;
using mint = modint998244353;
//using mint = modint1000000007;
using namespace std;
using ll = long long;
static const double pi = 3.141592653589793;
const int INF = (1 << 29);
const ll mod = 998244353;
// ifstream ifs("");
template<class T> void print(T& a){cout<<a<<'\n';}

int main(){

    int n,W;
    cin >> n >> W;

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

}