Tracing Mutual Recursive Methods

What is the output of the following program?

public class MutualRecursion {
    public static int a(int n) {
        if (n <= 0) return 0;
        return n - b(n-1);
    }
    public static int b(int n) {
        if (n <= 0) return 0;
        return n - a(n-1);
    }
    public static void main(String[] args) {
        System.out.println(a(3));
    }
}