#include <iostream>

using namespace std;

int main()
{
    float i=2.00;
    float mubiao=0;
    float sum=0;

    do
    {
        cin>>mubiao;

    {
        if(sum<mubiao)

        {
            sum=sum+1.00/i;
            i++;
        }
        cout<<i-2<<"card(s)";
        }
    }while(mubiao!=0);
    return 0;
}