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