s=input()
east_count=0
west_count=0
ans="NA"
for i in s:
    if i=="O":
        east_count+=1
        west_count=0
        if 3<=east_count:
            ans="East"
            break
    if i=="X":
        west_count+=1
        east_count=0
        if 3<=west_count:
            ans="West"
            break
print(ans)