View Code of Problem 51

#include <iostream>
using namespace std;
 
int main(){
	int n;
	cin>>n;
	int k;
	int sum;
	for(int i=0;i<n;i++){
		for(int j=0;j<n;j++){
			cin>>k;
			if(i<=j){
				sum+=k;
			}
	}
	}
	cout<<sum;
   return 0 ;
}