twonum = input().split()
socks = int(twonum[0])
newsocks = int(twonum[1])
days = 0

while socks > 0:
   socks -= 1
   if newsocks > 1:
      newsocks -= 1
   elif newsocks == 1:
      socks += 1
      newsocks = int(twonum[1])
   days += 1

print(days)