#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll linf=(1LL<<60) - 1;
const int inf=(1LL<<30) - 1;
const int mod=1000000007;
const int MOD=998244353;
const ll dx[] = {1, 0, -1, 0, 1, 1, -1, -1};
const ll dy[] = {0, 1, 0, -1, 1, -1, 1, -1};
#define overload4(a,b,c,d,name,...) name
#define rep1(n) for(long long _=0;_<n;++_)
#define rep2(i,n) for(long long i=0;i<n;++i)
#define rep3(i,a,b) for(long long i=a;i<b;++i)
#define rep4(i,a,b,c) for(long long i=a;i<b;i+=c)
#define rep(...) overload4(__VA_ARGS__,rep4,rep3,rep2,rep1)(__VA_ARGS__)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend() 
#define vec(type,name,...) vector<type> name(__VA_ARGS__)
#define vv(type,name,h,...) vector name(h,vector<type>(__VA_ARGS__))
#define vvv(type,name,h,w,...) vector name(h,vector(w,vector<type>(__VA_ARGS__)))
#define vvvv(type, name, h, w, n, ...) vector<vector<vector<vector<type>>>> name(h, vector<vector<vector<type>>>(w, vector<vector<type>>(n, vector<type>(__VA_ARGS__))))
struct Setting{ Setting(){ cin.tie(nullptr)->sync_with_stdio(0); fixed(cout).precision(12); } }Setting;
// #define _GLIBCXX_DEBUG
//-----------------------------------


void solve() {
    int N, W; cin >> N >> W;
    vector<int> v(N), w(N); 
    rep(i, N) cin >> v[i] >> w[i];
    int ans = -1;
    rep(i, N) if(w[i] <= W) ans = max(ans, v[i]);
    cout << ans << endl;
}
int main() {
    int T = 1;
    // cin >> T;
    while(T--) solve();
}