#include <bits/stdc++.h>

template<typename T>
class Array {
public:
  Array() {}
  Array(T* p_, int size_, int seek_) : p(p_), size(size_), seek(seek_) {}
  T *p;
  int size;
  int seek;
  T& operator [] (int y) {
    return p[seek+y];
  }
};

template<typename T>
Array<T> initArray(int n) {
  Array<T> res;
  res.p = new T [n + 3];
  res.size = n;
  res.seek = 0;
  return res;
}

template<typename T>
Array<T> loadArray(int n) {
  Array<T> res = initArray<T>(n);
  for(int i = 0; i < n; ++i) {
    scanf("%d", &res[i]);
  }
  return res;
}

template<typename T>
T head(Array<T> xs) {
  return xs[0];
}

template<typename T>
T last(Array<T> xs) {
  return xs[xs.size-1];
}

template<typename T>
Array<T> tail(Array<T> xs) {
  return Array<T>(xs.p, xs.size - 1, xs.seek + 1);
}

template<typename T>
Array<T> init(Array<T> xs) {
  return Array<T>(xs.p, xs.size - 1, xs.seek);
}

template<typename U, typename T>
U mean(Array<T> xs) {
  U res = 0;
  int n = xs.size;
  for(int i = 0; i < n; ++i) {
    res += xs[i];
  }
  return res / n;
}

template<typename T>
Array<T> sort(Array<T> xs) {
  Array<T> res = initArray<T>(xs.size);
  for(int i = 0; i < xs.size; ++i) {
    res[i] = xs[i];
  }
  std::sort(res.p, res.p + res.size);
  return res;
}

int main() {
  Array<int> xs = loadArray<int>(6);
  double res = mean<double>(init(tail(sort(xs))));
  printf("%.2lf\n", res);
  
  return 0;
}