class Fibonacci {

    public static void main(String[] arg) {
    	int n = 4;
    	n = fibonacci(n);
    	System.out.println(n);
    }
    
    static int fibonacci(int n) {
    	if (n <= 2) return 1;
    	int a = fibonacci(n - 1);
    	int b = fibonacci(n - 2);
    	return a + b;
    }
    
}