#yuki_486

s=raw_input()

east=0
west=0
i=0
while True:
 if len(s)<=i:
  print 'NA'
  break
 if s[i]=='O':
  east+=1
  west=0
 elif s[i]=='X':
  west+=1
  east=0
 if east>=3:
  print 'East'
  break
 elif west>=3:
  print 'West'
  break
 i+=1