#include <stdio.h>

int main(void) {
	int a=1,b=2,c,i,q,ans=0;
	for(i=1;c<1000;i++)
	{
		c = 3 * b + 2 * a;
		a = b;
		b = c;
		q = (c >= 100) && (c <= 1000);
		ans += q;
	}
	printf("answer:%d",ans);
	return 0;
}