#include <iostream>
#include <stdio.h>

int main()
{
    long n,k,t;
    scanf("%ld%ld",&n,&k);
    t=2*(n/k)+(n%k!=0)+((n%k>k/2.0)||(n<k));
    printf("%ld\n",t);
    return 0;
}

Edited by author 05.05.2012 14:45

Edited by author 05.05.2012 14:45

but sometimes 0.031. Don't know why..

Edited by author 05.05.2012 15:05

result is n/k+1 + (n-1+n%k)/k
to avoid WA8 check if k is greater than n.

Can you explain it for me? I can't understand this formular.(sorry for my English)