C++ :

undefined

Pascal :

undefined

#include<bits/stdc++.h>
using namespace std;
int a[100005],b[100005];
int main(){
	int n;
	cin>>n;
	for(int i=1;i<=n;i++){
		cin>>a[i]>>b[i];
	}
	int l=1,r=n;
	while(l<=r){
		
	}
	return 0;
}