#!/usr/bin/env python3
# -*- coding: utf-8 -*-

s = int(input())
a = s // 100
b = s % 100
if 1 <= a <= 12:
    if 1 <= b <= 12:
        print('AMBIGUOUS')
    else:
        print('MMYY')
else:
    if 1 <= b <= 12:
        print('YYMM')
    else:
        print('NA') s = int(input()) s int(input()) int input() input a = s // 100 a s // 100 s 100 b = s % 100 b s % 100 s 100 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 = int(input()) int(input()) s a = s // 100 s // 100 a b = s % 100 s % 100 b
#!/usr/bin/env python3
# -*- coding: utf-8 -*-

s = int(input())
a = s // 100
b = s % 100
if 1 <= a <= 12:
    if 1 <= b <= 12:
        print('AMBIGUOUS')
    else:
        print('MMYY')
else:
    if 1 <= b <= 12:
        print('YYMM')
    else:
        print('NA')