#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef unsigned long long ull;
typedef long double ld;
int dx[8] = { 1, 0, -1, 0, 1, 1, -1, -1 }, dy[8] = { 0, 1, 0, -1, 1, -1, 1, -1 };
const long long mod = 998244353;
const ll inf = 1LL << 60;
const int INF = 5e8;

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