What is the mistake tell please ???

Question

import java.util.*;
public class Program
{
public static void main(String[] args) {
Scanner s=new Scanner (System.in);
int a=s.nextInt();
Switch(a); {
case 1 : System.out.println("Hello");
break;
case 2 : System.out.println("Namaste");
break;
case 3 : System.out.println("Bonjour");
break;
default : System.out.println("Invalid number");
}
}
}