s = input()

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

if 1 <= int(s[:2]) <= 12:
    if 1 <= int(s[2:]) <= 12:
        print('AMBIGUOUS')
    else:
        print('MMYY')
else:
    if 1 <= int(s[2:]) <= 12:
        print('YYMM')
    else:
        print('NA')