#include <stdio.h>

int main(void)
{
    int a[6];
    int i = 0;
    int sum = 0;
    int max = 0;
    int min = 100;
    scanf("%d %d %d %d %d %d", &a[0], &a[1], &a[2], &a[3], &a[4], &a[5]);
    
    while(i < 6) {
        if (a[i] > max)
            max = a[i];
        if (a[i] < min)
            min = a[i];
        sum += a[i];
        i += 1;
    }
    sum = sum - max - min;

    printf("%.2f", (float)sum / 4);
   
    return 0;
}