s = input()
a = 1<= int(s[:2]) <=12
b = 1<= int(s[2:]) <=12
if a and b:
    print("AMBIGUOUS")
elif a:
    print('MMYY')
elif b:
    print('YYMM')
else:
    print('NA') s = input() s input() input a = 1<= int(s[:2]) <=12 a 1<= int(s[:2]) <=12 1<= int(s[:2]) 1 int(s[:2]) int s[:2] s :2 2 12 b = 1<= int(s[2:]) <=12 b 1<= int(s[2:]) <=12 1<= int(s[2:]) 1 int(s[2:]) int s[2:] s 2: 2 12 if a and b:
    print("AMBIGUOUS")
elif a:
    print('MMYY')
elif b:
    print('YYMM')
else:
    print('NA') a and b a b print("AMBIGUOUS") print "AMBIGUOUS" elif a:
    print('MMYY') a print('MMYY') print 'MMYY' elif b:
    print('YYMM') b print('YYMM') print 'YYMM' print('NA') print 'NA' a = 1<= int(s[:2]) <=12 1<= int(s[:2]) <=12 a s = input() input() s b = 1<= int(s[2:]) <=12 1<= int(s[2:]) <=12 b
s = input()
a = 1<= int(s[:2]) <=12
b = 1<= int(s[2:]) <=12
if a and b:
    print("AMBIGUOUS")
elif a:
    print('MMYY')
elif b:
    print('YYMM')
else:
    print('NA')