s = gets.chomp.split("")
east = 0
west = 0
s.each{|win|
  if win == "O"
    east += 1
    west = 0
  else
    east = 0
    west += 1
  end
  break if east>=3 || west>=3
}
j = "NA"
j = "East" if east>=3
j = "West" if west>=3
puts j