#include <iostream> #include <iomanip> using namespace std; int main() { int n; cin >> n; int total = 0; for (int i = 0; i < n; i++) { int len; cin >> len; total += (len + 69) / 70; } double money = total * 0.1; cout << fixed << setprecision(1) << money << endl; return 0; }