#include <stdio.h>

int main()
{
  long n,k;
  long res;
  while(scanf("%ld %ld",&n,&k)==2)
  {
    res=0;
	if(k<=1||k>n)
		res=n;
	else
	{
	  res=n;
	  long temp=n,r=0;
      while(temp>=k)
	  {
	    temp=n/k;
		res+=temp;
		r=n%k;
		n=temp+r;
	  }
	}
	printf("%ld\n",res);
  }
  return 0;
}