#include using namespace std; struct Initializer { Initializer() { cin.tie(0); ios::sync_with_stdio(0); cout << fixed << setprecision(15); } } initializer; template inline istream& operator>>(istream &s, vector &v) { for (T &t : v) s >> t; return s; } template inline ostream& operator<<(ostream &s, const vector &v) { for (const T &t : v) s << t << endl; return s; } template inline T min(vector& v) {return *min_element(v.begin(), v.end());} template inline T max(vector& v) {return *max_element(v.begin(), v.end());} template inline void sort(vector& v) {sort(v.begin(), v.end());} template inline void sort(vector& v, Function func) {sort(v.begin(), v.end(), func);} template inline void rsort(vector& v) {sort(v.rbegin(), v.rend());} template inline void reverse(vector& v) {reverse(v.begin(), v.end());} template inline void unique(vector& v) {v.erase(unique(v.begin(), v.end()), v.end());} template inline void nth_element(vector& v, int n) {nth_element(v.begin(), v.begin() + n, v.end());} template inline bool next_permutation(vector& v) {return next_permutation(v.begin(), v.end());} template inline int find(vector& v, T t) {return find(v.begin(), v.end(), t) - v.begin();} template inline int in(vector v, T t) {return find(v, t) != (int)v.size();} template inline int lower_bound(vector& v, T t) {return lower_bound(v.begin(), v.end(), t) - v.begin();} template inline int upper_bound(vector& v, T t) {return upper_bound(v.begin(), v.end(), t) - v.begin();} template inline T accumulate(const vector& v) {return accumulate(v.begin(), v.end(), T(0));} template inline void adjacent_difference(vector& v, vector& u) {adjacent_difference(v.begin(), v.end(), u.begin());} template inline void partial_sum(vector& v, vector& u) {partial_sum(v.begin(), v.end(), u.begin());} template inline T inner_product(vector& v, vector& u) {return inner_product(v.begin(), v.end(), u.begin(), T(0));} template inline int count_if(vector v, Function func) {return count_if(v.begin(), v.end(), func);} template inline void remove_if(vector& v, Function func) {v.erase(remove_if(v.begin(), v.end(), func), v.end());} template inline bool any_of(vector v, Function func) {return any_of(v.begin(), v.end(), func);} int main() { vector s(6); cin >> s; cout << setprecision(2) << (accumulate(s) - max(s) - min(s)) / 4.0 << endl; }