# include<stdio.h>
# define N 10
int main()
{
     int i = 0;
	float a[N];
	do
	{
		scanf("%f",&a[i++]);
	}while(a[i-1]!=0.00&&a[i-1]<=5.20&&a[i-1]>=0.01);

	for(int j = 0;j<i-1;j++)
	{
		float sum=0.00;
		for(int n=1;sum<a[j];n++)
			sum+=1.0/(n+1);

		printf("%d cards\n",n-1);
	}
	return 0;
}