#include<stdio.h>
//#include<iostream>
#include<math.h>
//using namespace std;
int main()
{
double n,k;
while(scanf("%lf%lf",&n,&k)==2)
{
if(n<=k)
printf("2\n");
else
printf("%.0lf\n",ceil(n*2.0/k));
}
}
原文：http://www.cnblogs.com/mycapple-zgs-111411/p/4619628.html