View Code of Problem 51

#include<stdio.h>
#include<string.h>


int main() {
	
	int n;
	scanf("%d", &n);
	int a[n][n];
	for (int i = 0;i < n;i++)
		for (int j = 0;j < n;j++)
			scanf("%d", &a[i][j]);

	int sum = 0;
	for (int i = 0;i < n;i++)
		for (int j = 0;j <= i;j++)
			sum += a[i][j];
	printf("%d\n", sum);


	
	return 0;

}