You have a digit sequence S of length 4. You are wondering which of the following formats S is in:
 - YYMM format: the last two digits of the year and the two-digit representation of the month (example: 01 for January), concatenated in this order
 - MMYY format: the two-digit representation of the month and the last two digits of the year, concatenated in this order
If S is valid in only YYMM format, print YYMM; if S is valid in only MMYY format, print MMYY; if S is valid in both formats, print AMBIGUOUS; if S is valid in neither format, print NA.

-----Constraints-----
 - S is a digit sequence of length 4.

-----Input-----
Input is given from Standard Input in the following format:
S

-----Output-----
Print the specified string: YYMM, MMYY, AMBIGUOUS or NA.

-----Sample Input-----
1905

-----Sample Output-----
YYMM

May XX19 is a valid date, but 19 is not valid as a month. Thus, this string is only valid in YYMM format.

Difficulty: introductory

Starter code:

Solutions:
s=input()
s1=int(s[0]+s[1])
s2=int(s[2]+s[3])
if (0<s1<13)and(0<s2<13):
    print("AMBIGUOUS")
elif (0<s1<13):
    print("MMYY")
elif (0<s2<13):
    print("YYMM")
else:
    print("NA")

s=input()
if 0 < int(s[:2]) <= 12 and 0 < int(s[2:]) <= 12:
  print('AMBIGUOUS')
elif 0 < int(s[:2]) <= 12 and int(s[2:]) >= 0:
  print('MMYY')
elif 0 < int(s[2:]) <= 12 and int(s[:2]) >= 0:
  print('YYMM')
else:
  print('NA')

s=str(input())
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 is_month(x):
  if 1 <= x <= 12:
    return True
  else:
    return False

S = input()
first, latter = is_month(int(S[:2])), is_month(int(S[2:]))
if first and latter:
  ans = "AMBIGUOUS"
elif not first and not latter:
  ans = "NA"
elif first:
  ans = "MMYY"
else:
  ans = "YYMM"
print(ans)

S = str(input())
L = int(S[0])*10 + int(S[1]) 
R = int(S[2])*10 + int(S[3]) 

if 12 >= L >= 1:
    if 12 >= R >= 1:
        print('AMBIGUOUS')
        return
    print('MMYY')
    return

else:
    if 12 >= R >= 1:
        print('YYMM')
        return
    print('NA')
    return

s = input()
if s == '0000' or (int(s[:2]) >= 13 and int(s[-2:]) >= 13):
    print('NA')
elif 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')

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

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

S = input()
 
if int(S[:2]) > 12 or int(S[:2]) == 0:
  if int(S[2:]) > 12 or int(S[2:]) == 0: print('NA')
  else: print('YYMM')
else:
  if int(S[2:]) > 12 or int(S[2:]) == 0: print('MMYY')
  else: print('AMBIGUOUS')

S=input()
if 1 <= int(S[0:2]) <= 12:
  if 1 <= int(S[2:4]) <= 12:
    print("AMBIGUOUS")
  else:
    print("MMYY")
else:
  if 1 <= int(S[2:4]) <= 12:
    print("YYMM")
  else:
    print("NA")

s = int(input())
l, r = s / 100, s % 100
if 1 <= l <= 12:
    if 1 <= r <= 12:
        print('AMBIGUOUS')
    else:
        print('MMYY')
elif 1 <= r <= 12:
    print('YYMM')
else:
    print('NA')


N = input()
A = int(N[:2])
B = int(N[2:])
if (A >= 1 and A <=12):
    if (B >= 1 and B <=12):
        print('AMBIGUOUS')
    else:
        print('MMYY')

else:
    if (B >= 1 and B <=12):
        print('YYMM')
    else:
        print('NA')

from itertools import product
s=input()
y=["0","1","2","3","4","5","6","7","8","9"]
yy=list((x+y for x,y in product(y,repeat=2)))
mm=["01","02","03","04","05","06","07","08","09","10","11","12"]

ans="NA"
if (s[0:2] in yy and s[2:4] in mm) and (s[0:2] not in mm or  s[2:4]  not in yy):
    ans="YYMM"
elif (s[0:2] in mm and s[2:4] in yy) and (s[0:2] not in yy or  s[2:4]  not in mm):
    ans="MMYY"
elif (s[0:2] in mm and s[2:4] in yy) and (s[0:2] in yy or  s[2:4]  in mm):
    ans="AMBIGUOUS"

print(ans)

S = input()
months = set([str(i).zfill(2) for i in range(1, 13)])

res = ''
if S[:2] in months and S[2:] in months:
    res = 'AMBIGUOUS'
elif S[:2] in months:
    res = 'MMYY'
elif S[2:] in months:
    res = 'YYMM'
else:
    res = 'NA'

print(res)

S = str(input())
year = int(S[0] + S[1])
month = int(S[2] + S[3])
if year <= 12 and year >= 1 and month >= 1 and month <= 12:
    print('AMBIGUOUS')
elif year >= 0 and year <= 99 and month >= 1 and month <= 12:
    print('YYMM')
elif year >= 1 and year <= 12 and month >= 0 and month <= 99:
    print('MMYY')
else:
    print('NA')

import sys

sys.setrecursionlimit(10 ** 8)
ini = lambda: int(sys.stdin.readline())
inl = lambda: [int(x) for x in sys.stdin.readline().split()]
ins = lambda: sys.stdin.readline().rstrip()
debug = lambda *a, **kw: print("\033[33m", *a, "\033[0m", **dict(file=sys.stderr, **kw))


def solve():
    S = ins()
    a = int(S[:2])
    b = int(S[2:])
    am = 0 < a < 13
    bm = 0 < b < 13
    if am and bm:
        return "AMBIGUOUS"
    elif am:
        return "MMYY"
    elif bm:
        return "YYMM"
    else:
        return "NA"


print(solve())


s = input()
s1 = s[:2]
s2 = s[2:4]
r = int(s2)
l = int(s1)

if(1<=r<=12 and 1<=l<=12):
    print("AMBIGUOUS")
elif((r > 12 or r == 0) and 1 <= l <= 12):
    print("MMYY")
elif((l >= 12 or l == 0) and 1 <= r <= 12):
    print("YYMM")
else:
    print("NA")




s = input()

flag=[0,0]

if 1<=int(s[0:2])<=12:
    flag[0]=1
if 1<=int(s[2:4])<=12:
    flag[1]=1

if flag==[0,0]:
    print("NA")
if flag==[1,0]:
    print("MMYY")
if flag==[0,1]:
    print("YYMM")
if flag==[1,1]:
    print("AMBIGUOUS")


S=input()
S_f=S[:2]
S_b=S[2:]

com=['YYMM','MMYY','AMBIGUOUS','NA']

if 1<=int(S_f)<=12:
  if 1<=int(S_b)<=12:
    print(com[2])
  else:
    print(com[1])
elif 1<=int(S_b)<=12:
  if 1<=int(S_f)<=12:
    print(com[2])
  else:
    print(com[0])
else:
  print(com[3])

S = int(input())
 
L = S // 100 # 前半2桁
R = S % 100 # 後半2桁
 
if 1 <= L <= 12:
  if 1 <= R <= 12: print('AMBIGUOUS')
  else: print('MMYY')
else:
  if 1 <= R <= 12: print('YYMM')
  else: print('NA')

S=input().strip()
a=int(S[:2])
b=int(S[2:])
aa = a < 13 and a != 0
bb = b < 13 and b != 0

if aa and bb:
    ans = 'AMBIGUOUS'
elif aa and not bb:
    ans = 'MMYY'
elif bb and not aa:
    ans = 'YYMM'
else:
    ans = 'NA'
print(ans)


s = input().rstrip()

a = int(s[:2])
b = int(s[2:])
if 1 <= a <= 12 and 1 <= b <= 12:
    print("AMBIGUOUS")
elif (a == 0 or 13 <= a <= 99) and 1 <= b <= 12:
    print("YYMM")
elif 1 <= a <= 12 and (b == 0 or 13 <= b <= 99):
    print("MMYY")
else:
    print("NA")

S = input()
num1 = int(S[:2])
num2 = int(S[2:])

if 1 <= num1 <= 12 and 1 <=  num2 <= 12:
    ans = "AMBIGUOUS"
elif 1 <= num1 <= 12 and (num2 == 0 or 12 < num2):
    ans = "MMYY"
elif (num1 == 0 or 12 < num1) and 1 <=  num2 <= 12:
    ans = "YYMM"
else:
    ans = "NA"
print(ans)


S = input()

first = int(S[0:2])
last = int(S[2:4])

if (0 < first < 13):
	if (0 < last < 13):
		print("AMBIGUOUS")
	else:
		print("MMYY")
else:
	if (0 < last < 13):
		print("YYMM")
	else:
		print("NA")

S = int(input())

flag = [0, 0] # [YYMM, MMYY]
l = S // 100
r = S % 100
if 1<=r and r<=12:
  flag[0] += 1
if 1<=l and l<=12:
  flag[1] += 1
if flag == [0, 0]:
  print('NA')
elif flag == [0, 1]:
  print('MMYY')
elif flag == [1, 0]:
  print('YYMM')
elif flag == [1, 1]:
  print("AMBIGUOUS")

s = input()

s1 = int(s[0]+s[1])
s2 = int(s[2]+s[3])
#print(s1, s2)
L=[]

for i in range(1, 13):
    L.append(i)


if s1 not in L and s2 not in L:
    print('NA')
elif s1 in L and s2 not in L:
    print('MMYY')
elif s1 not in L and s2 in L:
    print('YYMM')
else:
    print('AMBIGUOUS')


s = input()
head = int(s[:2])
tail = int(s[2:])

is_mmyy = False
is_yymm = False

if 1 <= head <= 12:
    is_mmyy = True

if 1 <= tail <= 12:
    is_yymm = True

if is_yymm and is_mmyy:
    print('AMBIGUOUS')
elif is_yymm:
    print('YYMM')
elif is_mmyy:
    print('MMYY')
else:
    print('NA')


s = str(input())
a = int(s[0]) * 10 + int(s[1])
b = int(s[2]) * 10 + int(s[3])
if 1 <= a <= 12 and 1 <= b <= 12:
    print('AMBIGUOUS')
elif 1 <= a <= 12:
    print('MMYY')
elif 1 <= b <= 12:
    print('YYMM')
else:
    print('NA')

s = int(input())
b = s%100
a = (s - b)//100
if (0 < a <= 12 and 0 < b <= 12):
    print("AMBIGUOUS")
elif (0 < a <= 12):
    print("MMYY")
elif (0 < b <= 12):
    print("YYMM")
else:
    print("NA")


S=input()
month=['01','02','03','04','05','06','07','08','09','10','11','12']
year=['00','01','02','03','04','05','06','07','08','09']
for i in range(10,100):
    year.append(str(i))

if month.count(S[0:2])==1 and year.count(S[2:4])==1 and month.count(S[2:4])==1 and year.count(S[0:2])==1:
    print('AMBIGUOUS')
elif month.count(S[2:4])==1 and year.count(S[0:2])==1:
    print('YYMM')
elif month.count(S[0:2])==1 and year.count(S[2:4])==1:
    print('MMYY')
else:
    print('NA')


s=input()

def month(n):
    if 1 <= n <= 12:
        return True
    else:
        return False


if int(s[0:2]) == 0:
    if month(int(s[2:4])) :
        print("YYMM")
        return
    else:
        print("NA")
        return

if int(s[2:4]) == 0:
    if month(int(s[0:2])):
        print("MMYY")
        return
    else:
        print("NA")
        return


if month(int(s[0:2])):
    if month(int(s[2:4])):
        print("AMBIGUOUS")
    else:
        print("MMYY")
else:
    if month(int(s[2:4])):
            print("YYMM")
    else:
        print("NA")


s = input()
s1 = int(s[:2])
s2 = int(s[2:])
if 1 <= s1 <= 12 and 1 <= s2 <= 12:
    print('AMBIGUOUS')
elif 1 <= s1 <= 12:
    print('MMYY')
elif 1 <= s2 <= 12:
    print('YYMM')
else:
    print('NA')

S = input()
f = int(S[:2])
l = int(S[2:])
if f==0 or f>12:
  if l==0 or l>12:
    print("NA")
  else:
    print("YYMM")
else:
  if l==0 or l>12:
    print("MMYY")
  else:
    print("AMBIGUOUS")

n = int(input())

r = n // 100
l = n % 100

if r <= 12 and 1 <= r:
  if l <= 12 and 1 <= l:
    print("AMBIGUOUS")
  else:
    print("MMYY")
else:
  if l <= 12 and 1 <= l:
    print("YYMM")
  else:
    print("NA")


s = input()
a=int(s[0:2])
b=int(s[2:4])
if 0<a<=12 and 0<b<=12:
    print('AMBIGUOUS')
elif 0<b<=12:
    print('YYMM')
elif 0<a<=12 :
    print('MMYY')

else:
    print('NA')



S=list(input())
month=["0"+str(i) for i in range(1,10)]
month.append("10")
month.append("11")
month.append("12")

First=S[:2]
Fmonthflag=0
if "".join(First) in month:
	Fmonthflag=1

Latter=S[2:]
Lmonthflag=0
if "".join(Latter) in month:
	Lmonthflag=1
	
if Fmonthflag==1 and Lmonthflag==0:
	print("MMYY")
elif Fmonthflag==0 and Lmonthflag==1:
	print("YYMM")
elif Fmonthflag==1 and Lmonthflag==1:
	print("AMBIGUOUS")
elif Fmonthflag==0 and Lmonthflag==0:
	print("NA")

s = input()

if 0 < int(s[:2]) <= 12 and 0 < int(s[2:]) <= 12:
    print('AMBIGUOUS')
elif 0 < int(s[:2]) <= 12 and int(s[2:]) >= 12:
    print('MMYY')
elif 0 < int(s[:2]) < 12 and int(s[2:]) == 0:
    print('MMYY')
elif int(s[:2]) >= 12 > 0 and 0 < int(s[2:]) <= 12:
    print('YYMM')
elif int(s[:2]) == 0 and 0 < int(s[2:]) <= 12:
    print('YYMM')
else:
    print('NA')

s = input()
a1 = int(s[:2])
a2 = int(s[2:])
if a1 in range(1, 13):
  if a2 in range(1, 13): print("AMBIGUOUS")
  else: print("MMYY")
else:
  if a2 in range(1, 13): print("YYMM")
  else: print("NA")

S = input()

F = int(S[:2])
B = int(S[2:])

if F == 0 and B == 0:
    print('NA')
elif (F == 0 and B > 12) or (B == 0 and F > 12):
    print('NA')
elif F == 0:
    print('YYMM')
elif B == 0:
    print('MMYY')
elif (F <= 12 and B <= 12):
    print('AMBIGUOUS')
elif F > 12 and B <= 12:
    print('YYMM')
elif F <= 12 and B > 12:
    print('MMYY')
else:
    print('NA')


s=input()
yy = ["%02d" % i for i in range(100)]
mm = ["%02d" % i for i in range(1, 13)]
yymm = s[:2] in yy and s[2:] in mm
mmyy = s[:2] in mm and s[2:] in yy
print((["NA","MMYY","YYMM","AMBIGUOUS"][yymm*2+mmyy]))


s = list(input())
s = [int(i+j) for (i,j) in zip(s[::2],s[1::2])]

if 1 <= s[0] <= 12:
  if 1 <= s[1] <= 12:
    print("AMBIGUOUS")
  else:
    print("MMYY")
else:
  if 1 <= s[1] <= 12:
    print("YYMM")
  else:
    print("NA")

import re


def answer(s: str) -> str:
    YYMM = r'^[0-9]{2}(0[1-9]|1[0-2])$'
    MMYY = r'^(0[1-9]|1[0-2])[0-9]{2}$'
    YYMM_result = re.match(YYMM, s)
    MMYY_result = re.match(MMYY, s)

    if YYMM_result and MMYY_result:
        return 'AMBIGUOUS'
    if YYMM_result:
        return 'YYMM'
    if MMYY_result:
        return 'MMYY'
    return 'NA'


def main():
    s = input()
    print((answer(s)))


def __starting_point():
    main()

__starting_point()

s = input()
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")

s = str(input())
num = ['01','02','03','04','05','06','07','08','09','10','11','12']
if s[:2] in num and s[2:] in num:
    print("AMBIGUOUS")
elif s[:2] in num:
    print("MMYY")
elif s[2:] in num:
    print("YYMM")
else:
    print("NA")

s = input()
if s[0:2] in "01 02 03 04 05 06 07 08 09 10 11 12":
  l = "m"
else:
  l = "y"
if s[2:4] in "01 02 03 04 05 06 07 08 09 10 11 12":
  r = "m"
else:
  r = "y"
if l+r == "mm":
  print("AMBIGUOUS")
elif l+r == "my":
  print("MMYY")
elif l+r == "ym":
  print("YYMM")
else:
  print("NA")

def f(y, m):
	if y in range(1, 13) and m in range(1, 13):
		return "AMBIGUOUS"
	if m in range(1, 13):
		return "YYMM"
	if y in range(1, 13):
		return "MMYY"
	return "NA"
  
S = input()
y, m = int(S[:2]), int(S[2:])
print((f(y, m)))
  


S=input()
s1=S[0:2]
s2=S[2:4]
li=["01","02","03","04","05","06","07","08","09","10","11","12"]

if s1 not in li:
    a=False
else:
    a=True
if s2 not in li:
    b=False
else:
    b=True

if a==b==True:
    print("AMBIGUOUS")
elif a==b==False:
    print("NA")
elif a==True:
    print("MMYY")
else:
    print("YYMM")


s = str(input())
s_ov = s[:2]
s_un = s[2:]

if int(s_ov) >= 1 and int(s_ov) <= 12:
    if int(s_un) >= 1 and int(s_un) <= 12:
        print("AMBIGUOUS")
    else:
        print("MMYY")
elif int(s_un) >= 1 and int(s_un) <= 12:
    print("YYMM")
else:
    print("NA")

S=input()

com=['YYMM','MMYY','AMBIGUOUS','NA']

if 1<=int(S[:2])<=12 and 1<=int(S[2:])<=12:
  print(com[2])
elif 1<=int(S[:2])<=12:
  print(com[1])
elif 1<=int(S[2:])<=12:
  print(com[0])
else:
  print(com[3])

S=input()
a=1<=int(S[:2])<=12
b=1<=int(S[-2:])<=12

if a & b: print('AMBIGUOUS')
elif a:   print('MMYY')
elif b:   print('YYMM')
else:     print('NA')

S = input()

former = int(S[:2])
latter = int(S[2:])

if((former >= 13 or former == 0) and 1 <= latter <= 12):
    print("YYMM")
if((latter >= 13 or latter == 0) and 1 <= former <= 12):
    print("MMYY")
if(1 <= former <= 12 and 1 <= latter <= 12):
    print("AMBIGUOUS")
if((former >= 13 or former == 0) and (latter >= 13 or latter == 0)):
    print("NA")

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

l = ["01","02","03","04","05","06","07","08","09","10","11","12"]

if a in l and b in l:
  print("AMBIGUOUS")
elif a in l and b not in l:
  print("MMYY")
elif a not in l and b in l:
  print("YYMM")
else:
  print("NA")

S = list(input())
x = int("".join(S[0:2]))
y = int("".join(S[2:4]))
if 1 <= x <= 12:
    if 1 <= y <= 12:
        print("AMBIGUOUS")
    else:
        print("MMYY")
else:
    if 1 <= y <= 12:
        print("YYMM")
    else:
        print("NA")
pass


S = input()

if int(S[2:]) == 0 or int(S[2:]) > 12:
    if int(S[:2]) == 0 or int(S[:2]) > 12:
        print('NA')
    else:
        print('MMYY')
elif int(S[:2]) == 0 or int(S[:2]) > 12:
    print('YYMM')
else:
    print('AMBIGUOUS')

s = input()
a = int(s[0:2])
b = int(s[2:])

if 13 <= a or a == 0:
    if 1 <= b and b <= 12:
        print('YYMM')
    else:
        print('NA')
else:
    
    if 1<= b  and b<= 12:
        print('AMBIGUOUS')
    else:
        print('MMYY')

s=input()

if 12<int(s[:2]) or 0==int(s[:2]):
    if 12>=int(s[2:])>=1:
        print("YYMM")
    else:
        print("NA")
elif 1<=int(s[:2])<=12:
    if 12>=int(s[2:])>=1:
        print("AMBIGUOUS")
    else:
        print("MMYY")
    


s = input()
ans = 'NA'
if 1 <= int(s[:2]) <= 12:
    ans = 'MMYY'
    if 1 <= int(s[2:]) <= 12:
        ans = 'AMBIGUOUS'
elif 1 <= int(s[2:]) <= 12:
    ans = 'YYMM'
print(ans)

S = input()
MM = ["01","02","03","04","05","06","07","08","09","10","11","12"]

if S[:2] in MM and S[2:] in MM:
  print("AMBIGUOUS")
elif S[:2] in MM:
  print("MMYY")
elif S[2:] in MM:
  print("YYMM")
else:
  print("NA")

S = int(input())
A = S//100
B = S%100
if 0 < A <= 12 and 0 < B <= 12:
    print("AMBIGUOUS")
elif 0 < A <= 12:
    print("MMYY")
elif 0 < B <= 12:
    print("YYMM")
else:
    print("NA")

s = input()
a = s[:2]
b = s[2:]
 
l = ["01","02","03","04","05","06","07","08","09","10","11","12"]
 
if a in l and b in l:
  print("AMBIGUOUS")
elif a in l and b not in l:
  print("MMYY")
elif a not in l and b in l:
  print("YYMM")
else:
  print("NA")


S=input()
l=len(S)
Y=0
M=0
for i in range(l):
    if i==3:
        if int(S[i-1])==0 and 1<=int(S[i])<=9:
            Y=1
        elif int(S[i-1])==1 and 0<=int(S[i])<=2:
            Y=1
for i in range(l):
    if i==1:
        if int(S[i-1])==0 and 1<=int(S[i])<=9:
            M=1
        elif int(S[i-1])==1 and 0<=int(S[i])<=2:
            M=1
if Y==1 and M==1:
    print('AMBIGUOUS')
elif Y==1 and M==0:
    print('YYMM')
elif Y==0 and M==1:
    print('MMYY')
elif Y==0 and M==0:
    print('NA')

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()

mae=int(s[:2])
ushiro=int(s[2:])

if 1<=mae<=12:
    if 1<=ushiro<=12:
        ans="AMBIGUOUS"
    else:
        ans="MMYY"

elif 1<=ushiro<=12:
    ans="YYMM"

else:
    ans="NA"
    
print(ans)

#Answer
S = input()
S = int (S)
A = S // 100
B = S % 100

if 1 <= A <= 12 and 1 <= B <= 12:
    print("AMBIGUOUS")
elif (A==0 or A > 12) and (B==0 or B > 12):
    print("NA")
elif (A==0 or A > 12) and 1 <= B <= 12:
    print("YYMM")
else:
    print("MMYY")

#ABC126 B

S = list(map(int,input()))
if 1 <= S[0]*10 + S[1] <= 12 and 1 <= S[2]*10 + S[3] <= 12:
    print("AMBIGUOUS")
elif 1 <= S[0]*10 + S[1] <= 12 and (S[2]*10 + S[3] > 12 or S[2]*10 + S[3] == 0):
    print("MMYY")
elif (S[0]*10 + S[1] > 12 or S[0]*10 + S[1] == 0)  and  1 <= S[2]*10 + S[3] <= 12:
    print("YYMM")
elif (S[0]*10 + S[1] > 12 or S[0]*10 + S[1] == 0) and (S[2]*10 + S[3] > 12 or S[2]*10 + S[3] == 0):
    print("NA")

import sys


def input(): return sys.stdin.readline().strip()
def I(): return int(input())
def LI(): return list(map(int, input().split()))
def IR(n): return [I() for i in range(n)]
def LIR(n): return [LI() for i in range(n)]
def SR(n): return [S() for i in range(n)]
def S(): return input()
def LS(): return input().split()


INF = float('inf')


def is_yymm(f, l):
    if 1 <= l <= 12:
        return True
    return False


def is_mmyy(f, l):
    if 1 <= f <= 12:
        return True
    return False


s = S()
f = int(s[:2])
l = int(s[2:])

if is_yymm(f, l) and is_mmyy(f, l):
    print('AMBIGUOUS')

elif is_yymm(f, l) and not(is_mmyy(f, l)):
    print('YYMM')

elif not(is_yymm(f, l)) and is_mmyy(f, l):
    print('MMYY')

else:
    print('NA')


s = int(input())
a = s // 100
b = s % 100

if 1 <= a <= 12 and 1 <= b <= 12:
    print("AMBIGUOUS")
elif 1 <= a <= 12:
    print("MMYY")
elif 1 <= b <= 12:
    print("YYMM")
else:
    print("NA")

import math


def isMM(num):
    if num < 13 and num > 0:
        return True
    else:
        return False


def hantei(number):
    num = math.floor(number/100)
    ber = number % 100
    if isMM(num) is False and isMM(ber) is False:
        return "NA"
    elif isMM(num) is True and isMM(ber) is True:
        return "AMBIGUOUS"
    elif isMM(num) is True and isMM(ber) is False:
        return "MMYY"
    else:
        return "YYMM"


num = int(input())
print((hantei(num)))


s = input()

s_1 = int(s[0:2])
s_2 = int(s[2:4])

if (s_1>12 or s_1<1) and (s_2>12 or s_2<1):
    print('NA')
elif s_1<=12 and s_1>=1 and s_2<=12 and s_2>=1:
    print('AMBIGUOUS')
elif s_1<=12 and s_1>=1:
    print('MMYY')
else:
    print('YYMM')

s = input()
l = s[:2]
r = s[2:]

if(int(l) >= 1 and int(l) <=12 and int(r) <= 12 and int(r) >= 1):
    print('AMBIGUOUS')
else :
    if(int(l) <= 12 and int(l) >= 1):
        print('MMYY')
    else:
        if(int(r) <= 12 and int(r) >= 1):
            print('YYMM')
        else:
            print('NA')


S = int(input())

a = int(S/100 - (S%100)/100)
b = int(S%100)

if( 0<a<13 and 0<b<13 ):
  print("AMBIGUOUS")
if( (0<a<13 and 12<b<100) or (0<a<13 and b==0) ):
  print("MMYY")
if( (12<a<100 and 0<b<13) or (a==0 and 0<b<13) ):
  print("YYMM")
if( 12<a<100 and 12<b<100 ):
  print("NA")
if( a==0 and 12<b<100 ):
  print("NA")
if( 12<a<100 and b==0 ):
  print("NA")
if( a==0 and b==0 ):
  print("NA")



s = str(input())
ans = ['YYMM','MMYY','AMBIGUOUS','NA']
#print(s[:2],s[-2:])
if (0==int(s[:2]) or 13<=int(s[:2])) and (0==int(s[-2:]) or 13<=int(s[-2:])):
    print((ans[3]))
if 0<int(s[:2])<=12 and 0<int(s[-2:])<=12:
    print((ans[2]))
elif 0<int(s[:2])<=12:
    print((ans[1]))
elif 0<int(s[-2:])<=12:
    print((ans[0]))



a=input()
b=int(a[0]+a[1])
c=int(a[2]+a[3])
if 1<=b<=12:
  if 1<=c<=12:
    print("AMBIGUOUS")
  else:
    print("MMYY")
else:
  if 1<=c<=12:
    print("YYMM")
  else:
    print("NA")

S = input()

if int(S[:2]) == 0 and 0 < int(S[2:]) <= 12:
  print("YYMM")
elif int(S[2:]) == 0 and 0 < int(S[:2]) <= 12:
  print("MMYY")
elif int(S[:2]) == 0 or int(S[2:]) == 0 or (int(S[:2]) > 12 and int(S[2:]) > 12):
  print("NA")
elif int(S[:2]) > 12 and int(S[2:]) <= 12:
  print("YYMM")
elif int(S[:2]) <= 12 and int(S[2:]) > 12:
  print("MMYY")
else:
  print("AMBIGUOUS")

s=int(input())
a=s//100
b=s%100
if 1<=a<=12 and 1<=b<=12:
  print("AMBIGUOUS")
elif 1<=a<=12 and (b>12 or b==0):
  print("MMYY")
elif (a==0 or a>12) and 1<=b<=12:
  print("YYMM")
else:
  print("NA")

n = input()
s, t = (1 <= int(n[:2]) <= 12), (1 <= int(n[2:]) <= 12)
print("AMBIGUOUS" if s and t else "YYMM" if t else "MMYY" if s else "NA")

S = int(input())

a = S//100
b = S%100

if 1<=a<=12 and 1<=b<=12:
    print('AMBIGUOUS')
elif 1<=a<=12 and (b>12 or b==0):
    print('MMYY')
elif (a==0 or a>12) and 1<=b<=12:
    print('YYMM')
else:
    print('NA')


S = input()
S_front = S[:2]
S_back = S[2:]

if 0 < int(S_front) < 13:
	if 0 < int(S_back) < 13:
		print("AMBIGUOUS")
	else:
		print("MMYY")
else:
	if 0 < int(S_back) < 13:
		print("YYMM")
	else:
		print("NA")

S = str(input())
F = S[:2]
L = S[2:]
if F == "00" or int(F)>12:
    if L == "00" or int(L) > 12:
        ans = "NA"
    else:
        ans = "YYMM"
elif int(F) <= 12:
    if int(L) >= 1 and int(L) <=12:
        ans = "AMBIGUOUS"
    else:
        ans = "MMYY"    
print(ans)

S = int(input())

L = S // 100 # 前半2桁
R = S % 100 # 後半2桁

if L > 12 or L == 0:
  if R > 12 or R == 0: print('NA')
  else: print('YYMM')
else:
  if R > 12 or R == 0: print('MMYY')
  else: print('AMBIGUOUS')

s = input()

if 1 <= int(s[2:4]) <= 12 and 1 <= int(s[0:2]) <= 12:
    print('AMBIGUOUS')
elif 1 <= int(s[2:4]) <= 12:
    print('YYMM')
elif 1 <= int(s[0:2]) <= 12:
    print('MMYY')
else:
    print('NA')

s = input()
def YYMM(s):
    p = int(s[2:])
    if 1 <= p <= 12:
        return True
    return False

def MMYY(s):
    p = int(s[:2])
    if 1 <= p <= 12:
        return True 
    return False

if YYMM(s) and MMYY(s):
    print('AMBIGUOUS')
elif YYMM(s):
    print('YYMM')
elif MMYY(s):
    print('MMYY')
else:
    print('NA')

S = input()
l = int(S[:2])
r = int(S[2:])
a = 0
ans = ['NA', 'MMYY', 'YYMM', 'AMBIGUOUS']
if 0 < l and l < 13:
  a += 1
if 0 < r and r < 13:
  a += 2
print(ans[a])

def check_month(month):
    return 1 <= int(month) <= 12

S = input()

ls = S[:2]
rs = S[2:]

if check_month(ls) and check_month(rs):
    print('AMBIGUOUS')
elif check_month(ls) and not check_month(rs):
    print('MMYY')
elif not check_month(ls) and check_month(rs):
    print('YYMM')
else:
    print('NA')

s = list(map(int,list(input())))
a = s[0]*10+s[1]
b = s[2]*10+s[3]
if a == 0 and b == 0:
    print('NA')
    return
if 0 < a<= 12 and (b>12 or b==0):
    print('MMYY')
elif (a > 12 or a==0) and 0 < b <= 12:
    print('YYMM')
elif a <= 12 and b <= 12:
    print('AMBIGUOUS')
else:print('NA')

S=input()
x=int(S[:2])
y=int(S[2:4])
if 1<=x<=12:
    if 1<=y<=12:
        print("AMBIGUOUS")
    else:
        print("MMYY")
else:
    if 1<=y<=12:
        print("YYMM")
    else:
        print("NA")

s=input()

if 0<int(s[:2])<=12:
    if 0<int(s[2:])<=12:
        print('AMBIGUOUS')
    else:
        print('MMYY')
else:
    if 0<int(s[2:])<=12:
        print('YYMM')
    else:
        print('NA')


def is_YY(S):
    N = int(S)
    if 00 <= N <= 99:
        return True
    else:
        return False


def is_MM(S):
    N = int(S)
    if 1 <= N <= 12:
        return True
    else:
        return False

def __starting_point():
    S = input()
    top = S[:2]
    bottom = S[2:]
    if is_YY(top) and is_MM(top) and is_YY(bottom) and is_MM(bottom):
        print('AMBIGUOUS')
    elif is_YY(top) and is_MM(bottom):
        print('YYMM')
    elif is_MM(top) and is_YY(bottom):
        print('MMYY')
    else:
        print('NA')
__starting_point()

s=input()
if int(s[0:2])>=1 and int(s[0:2])<=12:
    if int(s[2:4])>=1 and int(s[2:4])<=12:
        print("AMBIGUOUS")
    elif int(s[2:4])==0 or int(s[2:4])>=13:
        print("MMYY")
else:
    if int(s[2:4])>=1 and int(s[2:4])<=12:
        print("YYMM")
    else:
        print("NA")

s = str(input())
ans = "NA"
x = int(s[0:2])
y = int(s[2:4])
if x>0 and x<13:
    ans = "MMYY"
if y>0 and y<13:
    ans = "YYMM"
if x>0 and x<13 and y>0 and y<13:
    ans = "AMBIGUOUS"
print(ans)

YYMM = list(input())
YY = int(YYMM[0] + YYMM[1])
MM = int(YYMM[2] + YYMM[3])
YYMM = False
MMYY = False
if 1 <= MM <= 12:
  YYMM = True
if 1 <= YY <= 12:
  MMYY = True
if YYMM == True and MMYY == True:
  print("AMBIGUOUS")
elif YYMM == True and MMYY == False:
  print("YYMM")
elif YYMM == False and MMYY == True:
  print("MMYY")
elif YYMM == False and MMYY == False:
  print("NA")

s = input()

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

def yorm(i):
    flag = 'none'
    if 0<i<=12:
        flag = 'MM'
    elif i<100:
        flag = 'YY'
    return flag

bf = yorm(b)
af = yorm(a)
   
ans = bf+af
if len(ans) != 4:
    ans = 'NA'
if ans == 'MMMM':
    ans = 'AMBIGUOUS'
if ans == 'YYYY':
    ans = 'NA'
print(ans)

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

import re

s = input()


def is_valid_yymm(s):
    match = re.search('^[0-9]{2}(01|02|03|04|05|06|07|08|09|10|11|12)$', s)
    return bool(match)
    

def is_valid_mmyy(s):
    match = re.search('^(01|02|03|04|05|06|07|08|09|10|11|12)[0-9]{2}$', s)
    return bool(match)


if is_valid_yymm(s) and is_valid_mmyy(s):
    print('AMBIGUOUS')
elif is_valid_yymm(s):
    print('YYMM')
elif is_valid_mmyy(s):
    print('MMYY')
else:
    print('NA')


S = input()
ans = [0,0]

if 1<=int(S[:2]) and int(S[:2]) <= 12 :
    ans[0] = 1
if 1 <=int(S[2:]) and int(S[2:]) <= 12 :
    ans[1] = 1

if ans == [1,1] :
    print('AMBIGUOUS')
elif ans == [0,0] :
    print('NA')
elif ans == [0,1] :
    print('YYMM')
elif ans == [1,0] :
    print('MMYY')

s=input()
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 YY(x):
    if 1<=x and x<=12:
        return True
    else:
        return False
S=input()
A=int(S[0:2])
B=int(S[2:4])
if YY(A) and YY(B):
    print("AMBIGUOUS")
elif YY(A):
    print("MMYY")
elif YY(B):
    print("YYMM")
else:
    print("NA")


yymm = input()

if (1 <= int(yymm[0:2]) and int(yymm[0:2]) <= 12) and (1 <= int(yymm[2:4]) and int(yymm[2:4]) <= 12):
    print('AMBIGUOUS')
elif (1 <= int(yymm[0:2]) and int(yymm[0:2]) <= 12) and int(yymm[2:4]) <= 99:
    print('MMYY')
elif int(yymm[0:2]) <= 99 and (1 <= int(yymm[2:4]) and int(yymm[2:4]) <= 12):
    print('YYMM')
else:
    print('NA')

n = list(input())
x = int(n[0]+n[1])
y = int(n[2]+n[3])

if 1 <= x and x <= 12:
  if 1 <= y and y <= 12:
    print("AMBIGUOUS")
  else:
    print("MMYY")
elif 1 <= y and y <= 12:
  print("YYMM")
else:
  print("NA")

s = input()
a = s[0] + s[1]
b = s[2] + s[3]
p = 0
q = 0
if a == "01" or a == "02" or a == "03" or a == "04" or a == "05" or a == "06" or a == "07" or a == "08" or a == "09" or a == "10" or a == "11" or a == "12":
    p = 1
if b == "01" or b == "02" or b == "03" or b == "04" or b == "05" or b == "06" or b == "07" or b == "08" or b == "09" or b == "10" or b == "11" or b == "12":
    q = 1  
if p == 1 and q == 1:
    print("AMBIGUOUS")
elif p == 1 and q == 0:
    print("MMYY")
elif p == 0 and q == 1:
    print("YYMM")
else:
    print("NA")