#include <deque>
#include <algorithm>
#include <functional>
#include <iomanip>
#include <iostream>
#include <math.h>
#include <numeric>
#include <queue>
#include <stack>
#include <utility>
#include <vector>


using namespace std;


using ll = long long;
using ld = long double;


#define all(v) v.begin(), v.end()
#define rep(i, n) for (ll i = 0; i < n; ++i)
#define rep2(i, n, m) for (ll i = n; i <= m; ++i)
#define rep3(i, n, m) for (ll i = n; i >= m; --i)


template<class T> using pqg = priority_queue<T, vector<T>, greater<T>>;
template<class T> using pq  = priority_queue<T>;


template<class S, class T> inline bool chmax(S &a, T b) { if (a < b) { a = b; return true; } return false; }
template<class S, class T> inline bool chmin(S &a, T b) { if (a > b) { a = b; return true; } return false; }


int main() {
  int sum = 0, mn = 100, mx = 0;

  rep(i, 6) {
    int a;
    cin >> a;

    sum += a;
    chmin(mn, a);
    chmax(mx, a);
  }

  cout << fixed << setprecision(2) << (sum - mx - mn) / 4.0 << endl;
  return 0;
}