import sequtils, strutils
var
  x: seq[int] = stdin.readline.split.map(parseInt)
  ans: int = 0
while x[0] > 0 and x[1] > 0:
  x[0].dec
  x[1].dec
  ans.inc
  if x[0] == 0 and x[2] > 0:
    x[0].inc
    x[2].dec
  if x[1] == 0 and x[2] > 0:
    x[1].inc
    x[2].dec
echo ans