#include <stdio.h>

const int N = 25;

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

	int mult = 1;
	for (int i = 0, count = 0; i < N; i++)
	{
		if (count == 3)
			break;
		if (a[i] > 0)
		{
			mult *= a[i];
			count++;
		}
	}

	printf("%d\n", mult);
	
	return 0;
}