require "prime"
gets
a=gets.split.map(&:to_i)
x=0
a.each do |aa|
  next if aa==1
  a2=(aa**0.5).ceil
  i=2
  b=0
  while aa>1||i<=a2
    if aa%i==0
      aa/=i
      b+=1
    else
      i+=1
    end
  end
  x^=b
end
if x==0
  puts "black"
else
  puts "white"
end