#include <iostream>
using namespace std;
int dif(int x, int y){
if(x>y) return x-y;
else return y-x;
}
void ordine(){
int n, i, a, b, min=-1, ordine;
cin>>n;
for(i=1;i<=n;i++){
cin>>a>>b;
if(min==-1 || min>=dif(a,b)){
min=dif(a,b); ordine=i;
}
}
cout<<'\n';
cout<<ordine;
}
int main()
{
ordine();
return 0;
}