//USACO 2017 December Contest, Gold
//Problem 3. Haybale Feast
#include<bits/stdc++.h>
#define int long long
using namespace std;
void usaco(){
	freopen("hayfeast.in","r",stdin);
	freopen("hayfeast.out","w",stdout);
}
 
signed main() {
	ios::sync_with_stdio(false); cin.tie(nullptr);
	usaco();
	int n,m; cin>>n>>m;
	pair<int,int> a[n]; for(auto &[x,y]:a) cin>>x>>y; 
	int s=0,ans=2e18,j=0;
	multiset<int>st;
	for(int i=0;i<n;i++){
		auto [x,y]=a[i];
		s+=x; st.insert(y);
		while(j<i && s-a[j].first >=m) {
			st.erase(st.find(a[j].second));
			s-=a[j].first;
			j++;
		}
		if(s>=m) ans=min(ans,*st.rbegin());
	}
	cout<<ans;
}
 

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