#include <iostream> #include <iomanip> using namespace std; int main() { int n; cin >> n; double total_cost = 0.0; for (int i = 0; i < n; ++i) { int length; cin >> length; int segments = (length + 69) / 70; total_cost += segments * 0.1; } cout << fixed << setprecision(1) << total_cost << endl; return 0; }