import sequtils,strutils,algorithm,math,sugar,macros,strformat
macro unpack*(arr: auto,cnt: static[int]): auto =
  let t = genSym(); result = quote do:(let `t` = `arr`;())
  for i in 0..<cnt: result[1].add(quote do:`t`[`i`])

proc calcAll() :seq[seq[int]] =
  result = newSeqWith(101,newSeq[int](101))
  for a in 0..100:
    for b in 0..100:
      if a > b: continue
      var res = 0
      for i in a..b:
        if (a+b+i) mod 3 == 0: res += 1
      result[a][b] = res

const answers = calcAll()
let (a,b) = stdin.readLine().split().map(parseInt).unpack(2)
echo answers[a][b]