c#include <bits/stdc++.h> using namespace std; int main(){ cin.tie(0); cout.tie(0); ios_base::sync_with_stdio(false); int N; cin >> N; bool isBought = false; int ans = 987654321; for(int i = 0; i < N; i++){ int A, B; cin >> A >> B; if(A <= B){ ans = min(B, ans); isBought = true; } } if(isBought){ cout << ans << "\n"; }else{ cout << -1 << "\n"; } return 0; }