s=input()
winner="NA"
east_o=0
west_x=0
for i in s:
    if i=="O":
        east_o+=1
        west_x=0
    if i=="X":
        west_x+=1
        east_o=0
    if 3<=east_o:
        winner="EAST"
        break
    if 3<=west_x:
        winner="WEST"
        break
print(winner)