POJ1003-Hangover

#include<iostream>
using namespace std;
int main()
{
double c;
while (cin >> c) {
if (c < 1e-5) return 0;
float num = 1.0;
double length = 0.0 + 1 / (num + 1.0);
while (length - c < 0) {
num += 1.0;
length += 1 / (num + 1.0);
}
cout << int(num) << " card(s)" << endl;
}
return 0;
}