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

static int cmp(const void* n1, const void* n2)
{
	if (*(int*)n1 > *(int*)n2)
	{
		return 1;
	}
	else if (*(int*)n1 < *(int*)n2)
	{
		return -1;
	}
	else
	{
		return 0;
	}
}

int main()
{
	int S[6];
	for (int i = 0; i < 6; i++)
	{
		scanf("%d", &S[i]);
	}

	qsort(S, 6, sizeof(int), cmp);

	float sum = 0;
	for (int i = 1; i < 5; i++)
	{
		sum += S[i];
	}

	sum /= 4;

	float avg = round(sum * 100) / 100;
	
	printf("%.2f",avg);

	return 0;
}