1 #include <iostream>
 2 #include <stdio.h>
 3 #include <algorithm>
 4 using namespace std;
 5 
 6 int main()
 7 {
 8     freopen("in.txt", "r", stdin);
 9     int a[6];
10     double sum;
11     bool sign = 0;
12     while (1)
13     {
14         sign = 0;
15         sum = 0;
16         for (int i = 0; i < 6; i++)
17         {
18             cin >> a[i];
19             sign |= a[i];
20         }
21         if (!sign) break;
22         sort(a, a+6);
23         for (int i = 1; i < 5; i++)
24         {
25             sum += a[i];
26         }
27         cout << sum / 4 << endl;
28     }
29     return 0;
30 }