s = input()
a = int(s[:2])
b = int(s[2:])

if 0 < a < 13:
    if 0 < b < 13:
        print("AMBIGUOUS")
    else:
        print("MMYY")
else:
    if 0 < b < 13:
        print('YYMM')
    else:
        print('NA') s = input() s input() input a = int(s[:2]) a int(s[:2]) int s[:2] s :2 2 b = int(s[2:]) b int(s[2:]) int s[2:] s 2: 2 if 0 < a < 13:
    if 0 < b < 13:
        print("AMBIGUOUS")
    else:
        print("MMYY")
else:
    if 0 < b < 13:
        print('YYMM')
    else:
        print('NA') 0 < a < 13 0 < a 0 a 13 if 0 < b < 13:
        print("AMBIGUOUS")
    else:
        print("MMYY") 0 < b < 13 0 < b 0 b 13 print("AMBIGUOUS") print "AMBIGUOUS" print("MMYY") print "MMYY" if 0 < b < 13:
        print('YYMM')
    else:
        print('NA') 0 < b < 13 0 < b 0 b 13 print('YYMM') print 'YYMM' print('NA') print 'NA' b = int(s[2:]) int(s[2:]) b s = input() input() s a = int(s[:2]) int(s[:2]) a
s = input()
a = int(s[:2])
b = int(s[2:])

if 0 < a < 13:
    if 0 < b < 13:
        print("AMBIGUOUS")
    else:
        print("MMYY")
else:
    if 0 < b < 13:
        print('YYMM')
    else:
        print('NA')