#include <iostream.h>

int main()
{
	int score;
	cout << "Enter the test score: ";
	cin >> score;
	switch ( score /10 )
	{
	case 10:
	case 9: cout << 'A' << endl; break;
	case 8: cout << 'B' << endl; break;
	case 7: cout << 'C' << endl; break;
	case 6: cout << 'D' << endl; break;
	case 5:
	case 4:
	case 3:
	case 2:
	case 1:
	case 0: 

	default: cout << "Error: score is out of range.\n";
	}
	return 0;
	}