#include <stdio.h>

int main(void)
{
	const int n = 5;
	int matr[n][n];

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

	float sum = 0; 
	int count = 0;

	for (int i = 0; i < n; i++)
		for (int j = 0; j < n; j++)
			if (matr[i][j] < 0)
			{
				sum += matr[i][j];
				count++;
			}

	float sr = sum / count;

	printf("Arithmetic average: %f\n", sr);

	return 0;
}