#include <stdio.h>

int solution[41];

int main()
{
	int n;

	solution[0] = 1;
	solution[1] = 1;
	
	for (n = 2; n <= 40; n++)
		solution[n] = solution[n-1] + solution[n-2];
	
	for (;;) {
		scanf("%d", &n);

		if (n == 0)
			break;

		printf("%d\n", solution[n]);
	}
	return 0;
}