Problem:
Score : 200 points

Problem Statement

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 1

1905

Sample Output 1

YYMM

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

Sample Input 2

0112

Sample Output 2

AMBIGUOUS

Both December XX01 and January XX12 are valid dates. Thus, this string is valid in both formats.

Sample Input 3

1700

Sample Output 3

NA

Neither 0 nor 17 is valid as a month. Thus, this string is valid in neither format.

Solution in Pascal (FPC 2.6.2) (judge verdict: Wrong Answer)

uses crt;
var n,a,b:longint;
begin
        readln(n);
        a:=n div 100;
        b:=n mod 100;
        if(a<12)and(a<>0)and(b<>0)then write('AMBIGUOUS')else
        if(a=12)and(b=12)then write('AMBIGUOUS')else
        if(a>12)and(b>12)then write('NA')else
        if(a>12)and(b=0)then write('NA') else
        if(a=0)and(b=0)then write('NA')else
        if(a=0)and(b<>0)then write('NA')else 
        if (a<12)and(a>1)and(b>12)then write('MMYY') else
        if (a=12)and(b>12)then write('MMYY') else
        if (a=1)and(b>12)then write('MMYY') else
        if (a=12)and(b<=12)then write('MMYY') else
        if(a<>0)and(b<=1) then write('MMYY')else
        if (a=1)and(b>=1)then write('MMYY') else
        if (a>12)and(b<>0)and(b<=12)then write('YYMM');
        readln
end.