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

'''
Created on Dec 30, 2013

@author: JASHAN GOYAL
'''
def r(a,b,d,n,e):
    
    if(a<b):
        d+=(a+e)
        return d
    elif a==b:
        d=d+1+a
        return d
    d+=a
   # print d
    
    #c=(a+(e))/b
    #d+=c
    e=a%b
    a/=b
    n+=1
    return r(a,pow(b,1),d,n,e)


a,b=map(int,raw_input().split())
print r(a,b,0,1,a%b)