hdoj  acm   1555

#include <stdio.h>

int main()

{

    int n,m;

    int sum;

    while(scanf("%d%d",&n,&m))

    {

        sum=0;

        if(n==0&&m==0)

            break;

        if(n==0)

            printf("%d\n",sum);

        else

        {

            while(1)

            {

                if(n>=m)

                {

                    n=n-m;

                    sum+=m;

                    n=n+1;

                }

                else

                {

                    sum+=n;

                    break;

                }

            }

            printf("%d\n",sum);

        }

    }

    return 0;

}