main = interact straightWin
straightWin [] = "NA\n"
straightWin (r1:[]) = "NA\n"
straightWin (r1:r2:[]) = "NA\n"
straightWin (r1:r2:r3:rs) =
  if r1==r2&&r2==r3 then
    if r1=='O' then "East\n"
    else "West\n"
  else straightWin (r2:r3:rs)