team = ['East', 'West']
mark = ['O', 'X']
S = raw_input()
cnt = 0
flag = 0
straight = False
for i in range(0, len(S)):
	if S[i] == mark[flag]:
		cnt += 1
	else:
		flag = (flag+1)%2
		cnt = 1
	if cnt == 3:
		straight = True
		break
if straight: print team[flag]
else: print 'NA'