text: R, G, B = map(int, input().split())
  
  a = [R, G, B]
  
  
  def is_ok(n):
      m = 0
      p = 0
      for x in a:
          if x - n >= 0:
              p += (x - n) // 2
          else:
              m += n - x
      return p >= m
  
  
  for i in range(min(a), max(a) + 2):
      if is_ok(i):
          continue
      print(i - 1)
      break
  