#include<iostream>
#define loop(i,a,b) for(int i=a;i<b;i++)
#define rep(i,a) loop(i,0,a)
using namespace std;

int main(){
	int n,a,b,ans=0;
	cin>>n;
	int dt[100002]={};
	rep(i,n){
		cin>>a>>b;
		dt[a]++;
		dt[b+1]--;
	}
	int cnt=-1;
	loop(i,1,100002){
		dt[i]+=dt[i-1];
	}
	rep(i,n+2){
		if(dt[i]>=i-1)ans=i;
	}
	cout<<ans-1<<endl;
	return 0;
}