#include <stdio.h>
#include <stdlib.h>

int main(void)
{
	int n, m;

	scanf("%d%d", &n, &m);

	int **a = (int **)malloc(n*sizeof(int *));
	for (int i = 0; i < n; i++)
		a[i] = (int *)malloc(m*sizeof(int));
	
	int sum = 0;

	for (int i = 0; i < n; i++)
		for (int j = 0; j < m; j++)
		{
			scanf("%d", &a[i][j]);
			if (a[i][j] < 0) sum += a[i][j];
		}
	printf("Summa: %d", sum);

	return 0;
}