#include<iostream>
#include<vector>
using namespace std;
    
int main(){
    int n,a,b,maxs=0;
    cin >> n ;
    vector<int> c(100003,0),sum(100003,0);
    for (int i = 0; i < n ; i++) {
        cin >> a >> b;
        c[a]++;
        c[b+1]--;
    }
    sum[0]=1;
    for(int i=0; i<100002 ; i++){
        sum[i+1] = sum[i]+c[i+1];
    }
    for(int i=1;i<=100002;i++){
        if (sum[i]>=i) maxs = i;
    }
    cout << max(0,maxs-1) << endl;
    return 0;
    
    
}