#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
int swap(const void* a, const void* b);
int main(void)
{
    int judge[6]={0};
    float totalscore=0;
    for(int i=0;i<6;i++)
    {
        scanf("%d",&judge[i]);
    }
    qsort(judge, 6, sizeof(int), swap);
    for(int i=1;i<5;i++)
    {
        totalscore+=judge[i];
    }
    totalscore/=4;
    printf("%.2f",totalscore);
}
int swap(const void* a, const void* b)
{
	return *(int*)a - *(int*)b;
}