#include <iostream>

using namespace std;

int main()
{
	double percent;
	char letterGrd;

	cout << " Please input percent points" << endl;
	cin >> percent;

	// determine letter grade

	if (percent >= 90)
	    letterGrd = 'A';
	else
		if (percent >= 80) 
		   letterGrd = 'B';
     else 
		if (percent >= 70) 
		   letterGrd = 'C';	
	 else 
		if (percent >= 50) 
		   letterGrd = 'D';
	 else 
	    letterGrd = 'F';
	     
	cout << " Letter Grade is " << letterGrd << endl;

	switch (letterGrd)
	{
	case 'A' :
	          cout << " Excellent " << endl; 
			  break;
    case 'B' : 
		      cout << " Good job " << endl; 
			  break;
    case 'C' :
		      cout << " Try harder" << endl;
			  break;
    case 'D' :
		      cout << " Do your labs " << endl;
			  break;

    default  : cout << " Don't miss lectures " << endl;
	}

	return 0;
}