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. New Year Candles
# time limit per test1 second
# memory limit per test256 megabytes
# inputstandard input
# outputstandard output
# Vasily the Programmer loves romance, so this year he decided to illuminate his room with candles.
#
# Vasily has a candles.When Vasily lights up a new candle, it first burns for an hour and then it goes out. Vasily is smart, so he can make b went out candles into a new candle. As a result, this new candle can be used like any other new candle.
#
# Now Vasily wonders: for how many hours can his candles light up the room if he acts optimally well? Help him find this number.
#
# Input
# The single line contains two integers, a and b (1 ≤ a ≤ 1000; 2 ≤ b ≤ 1000).
#
# Output
# Print a single integer — the number of hours Vasily can light up the room for.


def solve_the_problem():

    result = 0
    a, b = [int(x) for x in input().split()]
    result += a
    while a > 0:
        result += int(a / b)
        a /= b
    print(result)



if __name__ == "__main__":
    solve_the_problem()
