#include "stdio.h"
int main(){
    int i,a,b,s=0,count=0,day;
    while(1){
        count=0;
        scanf("%d",&i);
        if(i==0)break; else{
            day=0;
            for(;i>0;i--){
                day++;
                scanf("%d%d",&a,&b);
                if((s<(a+b))&&((a+b)>8)){
                    count=day;
                    s=a+b;
                }
            }
        }
        printf("%d\n",count);
    }
}