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

import sys

local_launch = False
try:
    open('LOCAL').read()
    local_launch = True
except:
    pass

input_data = open('INPUT.txt').read() if local_launch else sys.stdin.read()
done = {'i': 0}
tokens = input_data.split()

def next_token():
    result = tokens[done['i']]
    done['i'] += 1
    return result

def next_int():
    return int(next_token())

def next_str():
    return next_token()

############## BEGIN OF CODE #####################
a = next_int()
b = next_int()

candles = a
burned = 0
parts = 0

while candles > 0:
    burned += candles
    parts += candles
    candles = parts // b
    parts %= b

print(burned)









############# END OF CODE #####################