s = input()
a = int(s[:2])
b = int(s[2:])

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

if 0<a<13:
    if 0<b<13:
        print("AMBIGUOUS")
    else:
        print("MMYY")
else:
    if 0<b<13:
        print("YYMM")
    else:
        print("NA")
