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

l = [int(i) for i in raw_input().split()]

a = l[0]
b = l[1]
rem = 0
k = a
rem=a%b
while ((a/b+rem))/b != 0:  
	k = k + a/b
	rem = a%b
#	print "a = ",a
#	print "rem = ",rem
	a = a/b+rem
 
print k+(a/b)
