#include<stdio.h>
int main(){
    int a[10],b[10];
    for(int i = 1;i<=7;++i){
        scanf("%d%d",&a[i],&b[i]);
        
    }
    for(int i = 1;i<=7;++i)if(a[i]+b[i]>8){ printf("%d",i);return 0;}
    printf("0");
    return 0;
}