int main()
{
  int k,n;
  double s;
  scanf("%d",&k);
  if(k<1||k>15)  printf("error");
  else
  {
    while(s<=k)
    {
      n=1;
      s=s+1/n;
      n=n+1;
    }
    printf("%d",n);
  }
  return 0;
}```