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

local m = {}
local lim = 1000 * 1000
for i = 1, lim do
  m[i] = {}
end
local tt = {0}
for i = 2, lim do
  local mi = m[i]
  for j = 1, lim do
    if not mi[j] then tt[i] = j break end
  end
  local v = tt[i]
  for j = i + i, lim, i do
    m[j][v] = true
  end
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")