A. Young Physicist Solution

#include<bits/stdc++.h>

using namespace std;

int main()

{

    int a[100][3],i,j,n;

    scanf("%d",&n);

    for (i=0;i<n;i++){

        for (j=0;j<3;j++){

            scanf("%d",&a[i][j]);

        }

    }

    int flag=0;

    int count=0;

    for (j=0;j<3;j++){

            count=0;

        for (i=0;i<n;i++){

            count+=a[i][j];

        }

        if (count!=0){

            flag=1;

            break;

        }

    }

    if (flag==0)

        cout<<"YES"<<endl;

    else if (flag==1)

        cout<<"NO"<<endl;

    return 0;

}