import java.util.Scanner;

class Main {
    public static void main(String[] args) {
        int result = fact(5);
        System.out.println("Результат: " + result);
    }

    public static int fact(int n) {

        System.out.println("Вход в fact(" + n + ")");

        if (n == 0) {
            System.out.println("fact(0) -> 0");
            return 0;
        } 
        else if (n == 1) {
            System.out.println("fact(1) -> 1");
            return 1;
        } 
        else {
            int a = fact(n - 2);
            int b = fact(n - 1);

            int result = a + b;

            System.out.println("fact(" + n + ") = fact(" + (n-2) + ") + fact(" + (n-1) + ") = " + result);

            return result;
        }
    }
}