#include <stdio.h>
int main(int argc, char *argv[])
{
	float c,oh;
	int i;
	while(scanf("%f",&c)&&c!=0.0)
	{
		i=1; oh=0;
		do
		{
			oh+=1.0/(i+1);
			++i;
		}while(oh<c);
		printf("%d card(s)\n",i-1);
	}
	return 0;
}