public class Solution {

    /**

     * @param n: an integer

     * @return: an ineger f(n)

     */

    public int fibonacci(int n) {

        // write your code here

        return foo(n);

    }

    public int foo(int x){

        if(x == 1){

            return 0;

        }

        else if(x == 2){

            return 1;

        }

        return foo(x-2) + foo(x - 1);

    }

}