using System;
public class Program
{
public static void Main()
char
mark = 'F';
switch (mark)
case 'A':
Console.WriteLine("excellent");
break;
case 'B':
Console.WriteLine("very good");
case 'C':
Console.WriteLine("good");
case 'D':
Console.WriteLine("pass");
case 'F':
Console.WriteLine("fail");
default:
Console.WriteLine("wrong mark");
}
