5.5

#include<iostream>#include<vector>#include<string>using namespace std;int main(){vector<string> scores = { "F", "D", "C", "B", "A", "A++" };for (int g; cin >> g;){string letter;if (g < 60)cout << (letter = scores[0]) << endl;else{letter = scores[(g - 50) / 10];if (g != 100)letter += g % 10>7 ? "+" : g % 10 < 3 ? "-" : "";cout << letter << endl;}}return 0;}