#include <stdio.h>

int f(int n)
{
	if (n == 0 || n == 1)
		return 1;
	else
		return f(n-1) + f(n-2);
}

int main()
{
	int n;
	
	for (;;) {
		scanf("%d", &n);

		if (n == 0)
			break;

		printf("%d\n", f(n));
	}
	return 0;
}