/* -*- coding: utf-8 -*-
 *
 * 394.cc: No.394 ハーフパイプ(1) - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int N = 6;

/* typedef */

typedef vector<int> vi;
typedef queue<int> qi;
typedef pair<int,int> pii;

/* global variables */

int as[N];

/* subroutines */

/* main */

int main() {
  int sum = 0;

  for (int i = 0; i < N; i++) (cin >> as[i]), sum += as[i];
  sort(as, as + N);

  sum -= as[0] + as[N - 1];
  int ave = sum * 100 / (N - 2);

  printf("%d.%02d\n", ave / 100, ave % 100);
  return 0;
}