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

int Compete(const void* a, const void* b)
{
    return *(int*)a - *(int*)b;
}


int main()
{
    int arr[7] = { 0 };
    while (scanf("%d %d %d %d %d %d %d", &arr[0], &arr[1], &arr[2], &arr[3], &arr[4], &arr[5], &arr[6]) != EOF)
    {
        qsort(arr,7,sizeof(int), Compete);
        printf("%.2f\n", (((double)arr[1] + (double)arr[2] + (double)arr[3] + (double)arr[4] + (double)arr[5]) / 5.0));
    }
    return 0;
}