大佬看看哪里错了

#include <bits/stdc++.h>
using namespace std;
long long n,schoolstudy=0,motherstudy=0,day=0,sum=0,mmax=0;
int main(){
    //freopen("unhappy.cpp","r",stdin);
    //freopen("unhappy.cpp","w",stdout);
    cin>>n;
    for(int i=1;i<=n;i++){
        cin>>schoolstudy>>motherstudy;
        sum=schoolstudy+motherstudy;
        if(sum>mmax && sum>8){
            mmax=sum;
            day=i;
        }else{
            cout<<"0";
        }
    }
    cout<<day;
    //fclose(stdin);
    //fclose(stdout);
    return 0;
}