S = input()
winner = "NA"
west_win = 0
east_win = 0
for i in S:
    if i=="O": 
        east_win += 1
        west_win = 0
    if i=="X":
        west_win += 1
        east_win = 0
    if east_win >= 3:
        winner = "East"
        break
    if west_win >= 3:
        winner = "West"
        break
print(winner)