from __future__ import division
from collections import Counter as ctr
from math import ceil, log, factorial, sqrt
# reads a line of input and converts into a list of ints
# 1 1 3 => [1, 1, 3]
def rl():
    return [int(i) for i in raw_input().split()]

# reads n lines of input (if n defined) and returns a list of strings
# where each element is a line in the input
# abc
# abcdef
# => ['abc', 'abcdef']
# if n not defined, read first line to get number of lines
# 2
# abc
# abcdef
# => ['abc', 'abcdef']
def rm(n=None):
    if n is None:
        n = input()
    return [raw_input() for i in range(n)]

# same as rm, except converts each line to a list of ints like rl
def rlm(n=None):
    if n is None:
        n = input()
    return [rl() for i in range(n)]

def yn(b):
    if b:
        print "YES"
    else:
        print "NO"

a, b = rl()

total = 0 
burned = 0
current = a
while True:
    total += current
    burned += current
    current = 0
    current = burned // b
    burned %= b
    if current+burned < b:
        break

print total + current