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

class candle:
    def __init__(self):
        self.out = False

    def __str__(self):
        return 'Candle went out:' + str(out)

    def light(self):
        self.out = True

    def stat(self):
        return self.out


a = raw_input('enter input')
a = a.split()

init = int(a[0])
divide = int(a[1])
out = 0
hour = 0
while init > 0:
    init -= 1
    out += 1
    if out == divide:
        out = 0
        init += 1

    hour += 1
    
print hour
