poj 1003 Hangover

#include <iostream>
using namespace std;

int main()
{
    double len;
    while(cin >> len && len)
    {
        double sum = 0.0;
        double i = 1.0;
        int n = 2;
        while(sum < len)
        {
            sum += i/n;
            ++n;
        }
        cout << n-2 << " card(s)" <<endl;
    }
    return 0;
}