#include<stdio.h>

unsigned int fib(int x){
	if (x < 2) {
		return 1;
	}
	else {
		int fx1 = fib(x - 1);
		int fx2 = fib(x - 2);
		return fx1 + fx2;
	}
}

int main(){
	printf("%d\n", fib(40));
	return 0;
}