s = input()
for c in s:
    if not '0'<=c<='9':
        print('NA')
        exit(0)
a = int(s[:2])
b = int(s[2:])
if 1<=a<=12 and 1<=b<=12:
    print('AMBIGUOUS')
elif 1<=a<=12:
    print('MMYY')
elif 1<=b<=12:
    print('YYMM')
else:
    print('NA') s = input() s input() input for c in s:
    if not '0'<=c<='9':
        print('NA')
        exit(0) c s if not '0'<=c<='9':
        print('NA')
        exit(0) not '0'<=c<='9' '0'<=c<='9' '0'<=c '0' c '9' print('NA') print 'NA' exit(0) exit 0 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 1<=a<=12 and 1<=b<=12:
    print('AMBIGUOUS')
elif 1<=a<=12:
    print('MMYY')
elif 1<=b<=12:
    print('YYMM')
else:
    print('NA') 1<=a<=12 and 1<=b<=12 1<=a<=12 1<=a 1 a 12 1<=b<=12 1<=b 1 b 12 print('AMBIGUOUS') print 'AMBIGUOUS' elif 1<=a<=12:
    print('MMYY') 1<=a<=12 1<=a 1 a 12 print('MMYY') print 'MMYY' elif 1<=b<=12:
    print('YYMM') 1<=b<=12 1<=b 1 b 12 print('YYMM') print 'YYMM' print('NA') print 'NA' a = int(s[:2]) int(s[:2]) a s = input() input() s b = int(s[2:]) int(s[2:]) b
s = input()
for c in s:
    if not '0'<=c<='9':
        print('NA')
        exit(0)
a = int(s[:2])
b = int(s[2:])
if 1<=a<=12 and 1<=b<=12:
    print('AMBIGUOUS')
elif 1<=a<=12:
    print('MMYY')
elif 1<=b<=12:
    print('YYMM')
else:
    print('NA')