#include <bits/stdc++.h> using namespace std; using ll = long long; using P = pair<ll,ll>; #define fix(x) fixed << setprecision(x) #define asc(x) x, vector<x>, greater<x> #define rep(i, n) for(ll i = 0; i < n; i++) #define all(x) (x).begin(),(x).end() template<class T>bool chmin(T&a, const T&b){if(a>b){a=b;return 1;}return 0;} template<class T>bool chmax(T&a, const T&b){if(a<b){a=b;return 1;}return 0;} constexpr ll INFLL = (1LL << 62), MOD = 998244353; constexpr int INF = (1 << 30); int main(){ cin.tie(nullptr); ios::sync_with_stdio(false); int n,w,ans = -1; cin >> n >> w; rep(i,n){ int a,b; cin >> a >> b; if(b<=w) chmax(ans,a); } cout << ans << '\n'; return 0; }