#include <stdio.h>
int compute_cards_number(double L)
{
int n = 1;
double sum = 0.5;
while (sum < L)
{
n++;
sum += 1.0 / (n + 1);
}
return n;
}
int main()
{
double L;
scanf("%lf", &L);
printf("L的值为:%lf\n", L);
while (L != 0)
{
int n = compute_cards_number(L);
printf("%d cards(s)\n", n);
scanf("%lf", &L);
}
return 0;
}