#include<bits/stdc++.h>
using namespace std;

int N;
int D[100005];
int main(){
  cin >> N;
  for(int i=0;i<N;i++){
    int a,b; cin >> a >> b;
    D[a]++; D[b+1]--;
  }
  D[0]++;

  int res = 0;
  for(int i=1;i<=N+1;i++){
    D[i] = D[i]+D[i-1];
    if( D[i] >= i ) res = i;
  }
  cout << res-1 << endl;
}