import sequtils,algorithm,math
proc getchar_unlocked():char {. importc:"getchar_unlocked",header: "<stdio.h>" .}
proc scan(): int =
  while true:
    var k = getchar_unlocked()
    if k < '0': break
    result = 10 * result + k.ord - '0'.ord

template times*(n:int,body) = (for _ in 0..<n: body)
template `max=`*(x,y) = x = max(x,y)
template `min=`*(x,y) = x = min(x,y)

var rgb = @[scan(),scan(),scan()]
var ans = 0
while true:
  rgb = rgb.filterIt(it > 0)
  if rgb.len == 0 : break
  # echo rgb,ans
  let x = rgb.max()
  let y = rgb.min()
  if rgb.len == 3: # 3つ
    rgb = rgb.mapIt(it - y)
    ans += y
  elif rgb.len == 2:
    if x <= 2 : break
    if x - y <= 1:
      let n = (x div 4).min(y div 4)
      ans += n
      rgb = @[x - 2 * n,y - 2 * n]
    else:
      let n = (x div 3).min(y)
      ans += n
      rgb = @[y - n,x - n * 3]
  elif rgb.len == 1:
    ans += x div 5
    break
echo ans