ACM1021：Fibonacci Again

#include <stdio.h>
#include <string.h>
#define N 1000001
int ans[N];

int main()
{
	int i;
	
	int n;
	memset(ans, 0, sizeof(ans));
	ans[0] = 7 % 3;
	ans[1] = 11 % 3;
	for (i = 2; i <= N; i++)
		ans[i] = (ans[i - 1] + ans[i - 2]) % 3;
	while (scanf("%d", &n) != EOF)
	{
		if (ans[n] == 0)
			printf("yes\n");
		else
			printf("no\n");
	}
	return 0;
}