POJ-1003-Hangover

#include<cstdio>
#include<cstring>
int main()
{
double n;
while(scanf("%lf",&n)&&n)
{
double sum=0;
for(int i=2;;i++)
{
sum+=(double)1/(double)i;
if(sum>=n)
{
printf("%d card(s)\n",i-1);
break;
}
}
}
return 0;
}