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.Scanner;

/*

 */

public class ex19 {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int m = in.nextInt();
        int whole = n;
        int rest = 0;
        int result = n;

        result += whole / m;
        whole /= m;
        rest = whole % m;

        while (whole != 0) {     //(whole != 0)
            result += whole / m;
            whole /= m;
            rest += whole % m;
            if(whole < m){
                rest += whole;
            }
        }

        while (rest > m) {
            result += rest / m;
            rest /= m;
            rest += rest % m;
        }

        System.out.println(result);
    }
}
