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