#include <iostream> 
  
 using namespace std; 
  
 int main() 
 { 
     int n, x, y, z, xsum(0), ysum(0), zsum(0); 
     cin >> n; 
  
     while (n--) 
     { 
         cin >> x >> y >> z; 
         xsum += x; 
         ysum += y; 
         zsum += z; 
     } 
  
     if (xsum == 0 && ysum == 0 && zsum == 0) 
     { 
         cout << "YES" << endl; 
     } 
     else 
     { 
         cout << "NO" << endl; 
     } 
  
     return 0; 
 }
	ما الغرض من while(n--)