#define _DEB123UG
#include <bits/stdc++.h>
using namespace std;
#define endl "\n"
#define fi first
#define se second
#define all(x) (x).begin(),(x).end() 
#define sz(x) (x).size()
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<ld, ld> pdd;
typedef vector<int> vi;
typedef vector<pii> vii;
const long double pi = acos(-1.0);
const int INF = 987654321;
const ll LLINF = 4e18;
const double eps = 1e-9;
template<class T>bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }
///

int main(){
#ifdef _DEBUG   
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif      
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    
    int N, W; cin >> N >> W;
    vector<pii>V(N); for(auto &v: V)  cin >> v.first >> v.second;
    int mx = -1;
    for(auto v: V){
        if(v.second <= W) chmax(mx, v.first);
    }
    cout << mx << endl;
    return 0;
}