using System;
public class MainClass {
static void Main() {
string resp;
Console.WriteLine("Enter command ('x' to end):");
while ((resp = (Console.ReadLine()).ToLower()) != "x") {
switch (resp) {
case "a":
Console.WriteLine("Doing Task A");
break;
case "b":
Console.WriteLine("Doing Task B");
break;
default:
Console.WriteLine("Bad choice");
break;
}
}
}
}