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

a, b = map(int, raw_input().split())
# total = 0
# while a > 0:
#     print a, total
#     total += a
#     a = a/b + a%b
#     print a, total
#     if a/b == 0:
#         print total+a
#         exit(0)
#     raw_input()
# print total

# left is # candles left from prev round
# a is num candles from curr round
total, left = 0, 0
while a > 0:
    total += a # burned 'a' more
    left += a # left is used to generate new candles
    a = left // b # create new candles
    left = left % b # remainder is what's left
print total


