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

def func(n):
    candles_he_has = n[0]
    candles_from_burnt_ones = n[1]
    counter = 0
    burnt = 0
    while candles_he_has>=1:
        burnt += 1
        candles_he_has -= 1
        counter += 1
        if burnt == candles_from_burnt_ones:
            candles_he_has += 1/candles_from_burnt_ones
            burnt = 0
            counter += 1
    print(counter)
n = list(map(int,input().split()))
func(n)