i was trying to rewrite the below code, i m using notepad

Question

public class SimCal{

public static void sum(int a, int b){
System.out.println(a + b);
}

public static void main(String[] args){
sum(3, 9);
}

}
into this
class SimpleCal{

public static void sum(int a, int b){
System.out.println(a + b);
}

}

public class SimpleCalMain{
public static void main(String[] args){
sum(3, 2);
}
}
but it doesn't work why.