5 3
 1000 3
 777 17
 4 3
 2 2
 100 4
 10 4
 999 2
 6 4
 1 2
 17 3
 1 4
 26 8
 91 5
 1 3
 1000 2
 20 3
 9 4
 123 5
 1000 1000
 3 2
 3 3
 80 970
 1000 4
 1 1000

7
 1499
 825
 5
 3
 133
 13
 1997
 7
 1
 25
 1
 29
 113
 1
 1999
 29
 11
 153
 1001
 5
 4
 80
 1333
 1

import java.util.*;
public class a379
{
    public static void main(String ar[])
    {
        Scanner ob=new Scanner(System.in);
        int n=ob.nextInt();
        int m=ob.nextInt();
        int r=n,x=n,result=n;
        while(true)
        {

            r=n/m;
            n=n/m;
            result+=r;
            if(r==1 || r==0)
                break;
        }
        if(x%2==0)
            System.out.println(result);
        else
            System.out.println(result+2);
    }
}
