צריך עזרה בתרגיל בC#

[mlnn]

תנסה ככה:

int x, y;
int check = 0;
 
            x = int.Parse(Console.ReadLine()); 
            y = int.Parse(Console.ReadLine()); 
			
               switch (x) 
               { 
                   case 0:
                       check=1;
					   break; 
                   case 15:
                       check=1;
					   break; 
                   case 30:
                       check=1;
					   break; 
                   case 40:
                       check=1;
					   break; 
                   case 60:
                       check=1;
					   break; 
                   default:
                       check=0;
               } 
                    

               switch (y) 
               { 
                   case 0:
                       check=1;
					   break; 
                   case 15:
                       check=1;
					   break; 
                   case 30:
                       check=1;
					   break; 
                   case 40:
                       check=1;
					   break; 
                   case 60:
                       check=1;
					   break; 
                   default:
                       check=0;
               } 
if(check!=0)
	Console.WriteLine(Math.Abs(x-y));
else
	Console.WriteLine("error");