#include <iostream>
using namespace std;

int main()
{
if (testScore < 60)
  cout << "Your grade is F.\n";
else if (testScore < 70)
  cout << "Your grade is D.\n";
else if (testScore < 80)
  cout << "Your grade is C.\n";
else if (testScore < 90)
  cout << "Your grade is B.\n";
else
  cout << "That is not a valid score.\n";
else if (testScore <= 100)
  cout << "Your grade is A.\n";

}