s = input().strip()
current_east = 0
current_west = 0
winner = None

for c in s:
    if c == 'O':
        current_east += 1
        current_west = 0
    else:
        current_west += 1
        current_east = 0
    
    if current_east >= 3 or current_west >= 3:
        winner = 'East' if current_east >= 3 else 'West'
        break

print(winner if winner is not None else 'NA')