/* 再帰を使った高速なフィボナッチ数列の実現 */
class Foo {
    public static void main (String[] args) {
    	System.out.println(fib3(10));
    }

    static int fib3 (int n) {
	return fib3_sub(1, 1, n);
    }

    static int fib3_sub (int previous, int current, int n) {
	if (n<=0) {
	    return previous;
	} else if (n==1) {
	    return current;
	} else {
	    return fib3_sub(current, previous+current, n-1);
	}
    }
}