import sys, os, math, bisect, itertools, collections, heapq, queue
# from scipy.sparse.csgraph import csgraph_from_dense, floyd_warshall
from decimal import Decimal
from collections import defaultdict

# import fractions

sys.setrecursionlimit(10000000)

ii = lambda: int(sys.stdin.buffer.readline().rstrip())
il = lambda: list(map(int, sys.stdin.buffer.readline().split()))
fl = lambda: list(map(float, sys.stdin.buffer.readline().split()))
iln = lambda n: [int(sys.stdin.buffer.readline().rstrip()) for _ in range(n)]

iss = lambda: sys.stdin.buffer.readline().decode().rstrip()
sl = lambda: list(map(str, sys.stdin.buffer.readline().decode().split()))
isn = lambda n: [sys.stdin.buffer.readline().decode().rstrip() for _ in range(n)]

lcm = lambda x, y: (x * y) // math.gcd(x, y)
# lcm = lambda x, y: (x * y) // fractions.gcd(x, y)

MOD = 10 ** 9 + 7
MAX = float('inf')


def main():
    if os.getenv("LOCAL"):
        sys.stdin = open("input.txt", "r")

    S = iss()
    if 1 <= int(S[:2]) <= 12 and 1 <= int(S[2:]) <= 12:
        print('AMBIGUOUS')
    elif 1 <= int(S[:2]) <= 12:
        print('MMYY')
    elif 1 <= int(S[2:]) <= 12:
        print('YYMM')
    else:
        print('NA')


if __name__ == '__main__':
    main() import sys, os, math, bisect, itertools, collections, heapq, queue sys os math bisect itertools collections heapq queue from decimal import Decimal from collections import defaultdict sys.setrecursionlimit(10000000) sys.setrecursionlimit sys setrecursionlimit 10000000 ii = lambda: int(sys.stdin.buffer.readline().rstrip()) ii lambda: int(sys.stdin.buffer.readline().rstrip()) int(sys.stdin.buffer.readline().rstrip()) int sys.stdin.buffer.readline().rstrip() sys.stdin.buffer.readline().rstrip sys.stdin.buffer.readline() sys.stdin.buffer.readline sys.stdin.buffer sys.stdin sys stdin buffer readline rstrip il = lambda: list(map(int, sys.stdin.buffer.readline().split())) il lambda: list(map(int, sys.stdin.buffer.readline().split())) list(map(int, sys.stdin.buffer.readline().split())) list map(int, sys.stdin.buffer.readline().split()) map int sys.stdin.buffer.readline().split() sys.stdin.buffer.readline().split sys.stdin.buffer.readline() sys.stdin.buffer.readline sys.stdin.buffer sys.stdin sys stdin buffer readline split fl = lambda: list(map(float, sys.stdin.buffer.readline().split())) fl lambda: list(map(float, sys.stdin.buffer.readline().split())) list(map(float, sys.stdin.buffer.readline().split())) list map(float, sys.stdin.buffer.readline().split()) map float sys.stdin.buffer.readline().split() sys.stdin.buffer.readline().split sys.stdin.buffer.readline() sys.stdin.buffer.readline sys.stdin.buffer sys.stdin sys stdin buffer readline split int(sys.stdin.buffer.readline().rstrip()) for _ in range(n) for _ in range(n) _ range(n) range n for _ in range(n) int(sys.stdin.buffer.readline().rstrip()) int sys.stdin.buffer.readline().rstrip() sys.stdin.buffer.readline().rstrip sys.stdin.buffer.readline() sys.stdin.buffer.readline sys.stdin.buffer sys.stdin sys stdin buffer readline rstrip iln = lambda n: [int(sys.stdin.buffer.readline().rstrip()) for _ in range(n)] iln lambda n: [int(sys.stdin.buffer.readline().rstrip()) for _ in range(n)] [int(sys.stdin.buffer.readline().rstrip()) for _ in range(n)] n iss = lambda: sys.stdin.buffer.readline().decode().rstrip() iss lambda: sys.stdin.buffer.readline().decode().rstrip() sys.stdin.buffer.readline().decode().rstrip() sys.stdin.buffer.readline().decode().rstrip sys.stdin.buffer.readline().decode() sys.stdin.buffer.readline().decode sys.stdin.buffer.readline() sys.stdin.buffer.readline sys.stdin.buffer sys.stdin sys stdin buffer readline decode rstrip sl = lambda: list(map(str, sys.stdin.buffer.readline().decode().split())) sl lambda: list(map(str, sys.stdin.buffer.readline().decode().split())) list(map(str, sys.stdin.buffer.readline().decode().split())) list map(str, sys.stdin.buffer.readline().decode().split()) map str sys.stdin.buffer.readline().decode().split() sys.stdin.buffer.readline().decode().split sys.stdin.buffer.readline().decode() sys.stdin.buffer.readline().decode sys.stdin.buffer.readline() sys.stdin.buffer.readline sys.stdin.buffer sys.stdin sys stdin buffer readline decode split sys.stdin.buffer.readline().decode().rstrip() for _ in range(n) for _ in range(n) _ range(n) range n for _ in range(n) sys.stdin.buffer.readline().decode().rstrip() sys.stdin.buffer.readline().decode().rstrip sys.stdin.buffer.readline().decode() sys.stdin.buffer.readline().decode sys.stdin.buffer.readline() sys.stdin.buffer.readline sys.stdin.buffer sys.stdin sys stdin buffer readline decode rstrip isn = lambda n: [sys.stdin.buffer.readline().decode().rstrip() for _ in range(n)] isn lambda n: [sys.stdin.buffer.readline().decode().rstrip() for _ in range(n)] [sys.stdin.buffer.readline().decode().rstrip() for _ in range(n)] n lcm = lambda x, y: (x * y) // math.gcd(x, y) lcm lambda x, y: (x * y) // math.gcd(x, y) (x * y) // math.gcd(x, y) x * y x y math.gcd(x, y) math.gcd math gcd x y x y MOD = 10 ** 9 + 7 MOD 10 ** 9 + 7 10 ** 9 10 9 7 MAX = float('inf') MAX float('inf') float 'inf' def main():
    if os.getenv("LOCAL"):
        sys.stdin = open("input.txt", "r")

    S = iss()
    if 1 <= int(S[:2]) <= 12 and 1 <= int(S[2:]) <= 12:
        print('AMBIGUOUS')
    elif 1 <= int(S[:2]) <= 12:
        print('MMYY')
    elif 1 <= int(S[2:]) <= 12:
        print('YYMM')
    else:
        print('NA') main if os.getenv("LOCAL"):
        sys.stdin = open("input.txt", "r")

     os.getenv("LOCAL") os.getenv os getenv "LOCAL" sys.stdin = open("input.txt", "r") sys.stdin sys stdin open("input.txt", "r") open "input.txt" "r" S = iss() S iss() iss if 1 <= int(S[:2]) <= 12 and 1 <= int(S[2:]) <= 12:
        print('AMBIGUOUS')
    elif 1 <= int(S[:2]) <= 12:
        print('MMYY')
    elif 1 <= int(S[2:]) <= 12:
        print('YYMM')
    else:
        print('NA') 1 <= int(S[:2]) <= 12 and 1 <= int(S[2:]) <= 12 1 <= int(S[:2]) <= 12 1 <= int(S[:2]) 1 int(S[:2]) int S[:2] S :2 2 12 1 <= int(S[2:]) <= 12 1 <= int(S[2:]) 1 int(S[2:]) int S[2:] S 2: 2 12 print('AMBIGUOUS') print 'AMBIGUOUS' elif 1 <= int(S[:2]) <= 12:
        print('MMYY')
     1 <= int(S[:2]) <= 12 1 <= int(S[:2]) 1 int(S[:2]) int S[:2] S :2 2 12 print('MMYY') print 'MMYY' elif 1 <= int(S[2:]) <= 12:
        print('YYMM')
     1 <= int(S[2:]) <= 12 1 <= int(S[2:]) 1 int(S[2:]) int S[2:] S 2: 2 12 print('YYMM') print 'YYMM' print('NA') print 'NA' if __name__ == '__main__':
    main() __name__ == '__main__' __name__ '__main__' main() main il = lambda: list(map(int, sys.stdin.buffer.readline().split())) lambda: list(map(int, sys.stdin.buffer.readline().split())) il iln = lambda n: [int(sys.stdin.buffer.readline().rstrip()) for _ in range(n)] lambda n: [int(sys.stdin.buffer.readline().rstrip()) for _ in range(n)] iln lcm = lambda x, y: (x * y) // math.gcd(x, y) lambda x, y: (x * y) // math.gcd(x, y) lcm def main():
    if os.getenv("LOCAL"):
        sys.stdin = open("input.txt", "r")

    S = iss()
    if 1 <= int(S[:2]) <= 12 and 1 <= int(S[2:]) <= 12:
        print('AMBIGUOUS')
    elif 1 <= int(S[:2]) <= 12:
        print('MMYY')
    elif 1 <= int(S[2:]) <= 12:
        print('YYMM')
    else:
        print('NA') def main():
    if os.getenv("LOCAL"):
        sys.stdin = open("input.txt", "r")

    S = iss()
    if 1 <= int(S[:2]) <= 12 and 1 <= int(S[2:]) <= 12:
        print('AMBIGUOUS')
    elif 1 <= int(S[:2]) <= 12:
        print('MMYY')
    elif 1 <= int(S[2:]) <= 12:
        print('YYMM')
    else:
        print('NA') main ii = lambda: int(sys.stdin.buffer.readline().rstrip()) lambda: int(sys.stdin.buffer.readline().rstrip()) ii isn = lambda n: [sys.stdin.buffer.readline().decode().rstrip() for _ in range(n)] lambda n: [sys.stdin.buffer.readline().decode().rstrip() for _ in range(n)] isn fl = lambda: list(map(float, sys.stdin.buffer.readline().split())) lambda: list(map(float, sys.stdin.buffer.readline().split())) fl iss = lambda: sys.stdin.buffer.readline().decode().rstrip() lambda: sys.stdin.buffer.readline().decode().rstrip() iss MOD = 10 ** 9 + 7 10 ** 9 + 7 MOD sl = lambda: list(map(str, sys.stdin.buffer.readline().decode().split())) lambda: list(map(str, sys.stdin.buffer.readline().decode().split())) sl MAX = float('inf') float('inf') MAX
import sys, os, math, bisect, itertools, collections, heapq, queue
# from scipy.sparse.csgraph import csgraph_from_dense, floyd_warshall
from decimal import Decimal
from collections import defaultdict

# import fractions

sys.setrecursionlimit(10000000)

ii = lambda: int(sys.stdin.buffer.readline().rstrip())
il = lambda: list(map(int, sys.stdin.buffer.readline().split()))
fl = lambda: list(map(float, sys.stdin.buffer.readline().split()))
iln = lambda n: [int(sys.stdin.buffer.readline().rstrip()) for _ in range(n)]

iss = lambda: sys.stdin.buffer.readline().decode().rstrip()
sl = lambda: list(map(str, sys.stdin.buffer.readline().decode().split()))
isn = lambda n: [sys.stdin.buffer.readline().decode().rstrip() for _ in range(n)]

lcm = lambda x, y: (x * y) // math.gcd(x, y)
# lcm = lambda x, y: (x * y) // fractions.gcd(x, y)

MOD = 10 ** 9 + 7
MAX = float('inf')


def main():
    if os.getenv("LOCAL"):
        sys.stdin = open("input.txt", "r")

    S = iss()
    if 1 <= int(S[:2]) <= 12 and 1 <= int(S[2:]) <= 12:
        print('AMBIGUOUS')
    elif 1 <= int(S[:2]) <= 12:
        print('MMYY')
    elif 1 <= int(S[2:]) <= 12:
        print('YYMM')
    else:
        print('NA')


if __name__ == '__main__':
    main()
