local bxor = bit.bxor
local mce, mfl, msq, mmi, mma, mab = math.ceil, math.floor, math.sqrt, math.min, math.max, math.abs

local function getprimes(x)
  local primes = {}
  local allnums = {}
  for i = 1, x do allnums[i] = true end
  for i = 2, x do
    if allnums[i] then
      table.insert(primes, i)
      local lim = mfl(x / i)
      for j = 2, lim do
        allnums[j * i] = false
      end
    end
  end
  return primes
end

local function getdivisorparts(x, primes)
  local prime_num = #primes
  local tmp = {}
  local lim = mce(msq(x))
  local primepos = 1
  local dv = primes[primepos]
  while primepos <= prime_num and dv <= lim do
    if x % dv == 0 then
      local t = {}
      t.p = dv
      t.cnt = 1
      x = mfl(x / dv)
      while x % dv == 0 do
        x = mfl(x / dv)
        t.cnt = t.cnt + 1
      end
      table.insert(tmp, t)
      lim = mce(msq(x))
    end
    if primepos == prime_num then break end
    primepos = primepos + 1
    dv = primes[primepos]
  end
  if x ~= 1 then
    local t = {}
    t.p, t.cnt = x, 1
    table.insert(tmp, t)
  end
  return tmp
end

local tt = {0}

local function getdivisorCore(divisorparts)
  local m = {}
  local pat = 1
  local len = #divisorparts
  local allpat = 1
  for i = 1, len do
    allpat = allpat * (1 + divisorparts[i].cnt)
  end
  for t_i_pat = 0, allpat - 2 do
    local div = allpat
    local i_pat = t_i_pat
    local ret = 1
    for i = 1, len do
      div = mfl(div / (divisorparts[i].cnt + 1))
      local mul = mfl(i_pat / div)
      i_pat = i_pat % div
      for j = 1, mul do
        ret = ret * divisorparts[i].p
      end
    end
    m[tt[ret]] = true
  end
  for i = 0, 1000000 do
    if not m[i] then return i end
  end
  assert(false)
  return false
end

local function getdivisor(x, primes)
  local dvp = getdivisorparts(x, primes)
  return getdivisorCore(dvp)
end


local primes = getprimes(1000)

for i = 2, 1000 * 1000 do
  tt[i] = getdivisor(i, primes)
end
-- print(os.clock())
-- os.exit()
local n = io.read("*n", "*l")
local ret = 0
local s = io.read()
for w in s:gmatch("%d+") do
  local a = tonumber(w)
  ret = bxor(ret, tt[a])
end
print(ret == 0 and "black" or "white")