S=input()
a,b=int(S[:2]),int(S[2:])
if 0<a<13 and 0<b<13:
    print('AMBIGUOUS')
elif 0<a<13:
    print('MMYY')
elif 0<b<13:
    print('YYMM')
else:
    print('NA') S=input() S input() input a,b=int(S[:2]),int(S[2:]) a int(S[:2]) int S[:2] S :2 2 b int(S[2:]) int S[2:] S 2: 2 if 0<a<13 and 0<b<13:
    print('AMBIGUOUS')
elif 0<a<13:
    print('MMYY')
elif 0<b<13:
    print('YYMM')
else:
    print('NA') 0<a<13 and 0<b<13 0<a<13 0<a 0 a 13 0<b<13 0<b 0 b 13 print('AMBIGUOUS') print 'AMBIGUOUS' elif 0<a<13:
    print('MMYY') 0<a<13 0<a 0 a 13 print('MMYY') print 'MMYY' elif 0<b<13:
    print('YYMM') 0<b<13 0<b 0 b 13 print('YYMM') print 'YYMM' print('NA') print 'NA' S=input() input() S a,b=int(S[:2]),int(S[2:]) int(S[:2]) a b=int(S[:2]),int(S[2:]) int(S[2:]) b
S=input()
a,b=int(S[:2]),int(S[2:])
if 0<a<13 and 0<b<13:
    print('AMBIGUOUS')
elif 0<a<13:
    print('MMYY')
elif 0<b<13:
    print('YYMM')
else:
    print('NA')