hdu1056

#include <cstdio>

void main() { double length; double l[300]; l[1] = 1.0/2; int i; for (i = 2;; ++i) { l[i] = l[i-1] + 1.0/(i+1); if (l[i] >= 5.20) break; } while (scanf("%lf", &length), length > 0) { for (i = 1;; ++i) { if (l[i] >= length) break; } printf("%d card(s)\n",i); } }