#include <iostream>
#include <stdio.h>
#include <vector>

using namespace std;

using i64 = long long;

#define yn(pope) (pope ? "Yes" : "No")

#define rep(i, n, m) for (int i = (n); i < (m); i++)
#define rrep(i, n, m) for (int i = (n); i > m; i--)

#define IINF (1 << 30)
#define INF (1ll << 60)

#define all(v) v.begin(), v.end()

int main() {
  int N, W; cin >> N >> W;

  int ans = -1;

  rep(i, 0, N) {
    int v, w; cin >> v >> w;

    if (w <= W) {
      ans = max(ans, v);
    }
  }

  cout << ans << endl;

  return 0;
}