What is wrong here plis help

Question

public class MyClass {

static int sum(int val1, int val2) {
return val1 + val2;
}
}

class MainClass{
public static void main(String[ ] args) {
//int x = sum(2, 5);
//System.out.println(x);
sum(2, 3);
}
}

Answer 1

MainClass cant see function sum because it is in MyClass.
solution: 1 replace sum function into class MainClass.
solution 2: Use MyClass.sum() instead of sum()