#include <iostream>
using namespace std;

int main()
{
    /*
    Assign a letter grade for

         90 - 100% = A
           80 - 89% = B
           70 - 79% = C
           60 - 69% = D
     less than 60% = F
    */
    int percent, percent_div10;
    cout << "Enter a percent => ";
    cin >> percent;                   // 87
    percent_div10 = percent / 10;     // 8
    char grade;

    if (percent_div10 > 8) grade = 'A';
    else if (percent_div10 > 7) grade = 'B';
    else if (percent_div10 > 6) grade = 'C';
    else if (percent_div10 > 5) grade = 'D';
    else if (percent_div10 > 0) grade = 'F';
    else {}

    cout << grade << endl;


}