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 C (GCC 5.4.1) (judge verdict: Accepted)

#include<stdio.h>
#include<stdlib.h>

int main(void){
    int s,n4,n3,n2,n1,f,l;

    scanf("%d",&s);

    for(n4 = 0; s >= 1000; n4++){
        s = s - 1000;
    }
    for(n3 = 0; s >= 100; n3++){
        s = s - 100;
    }
    for(n2 = 0; s >= 10; n2++){
        s = s - 10;
    }
    for(n1 = 0; s >= 1; n1++){
        s = s - 1;
    }

    f = 10*n4 + n3;
    l = 10*n2 + n1;
    

    if(f >= 1 && f <= 12){
        if(l >= 1 && l <= 12){
            printf("AMBIGUOUS");
        }else{
            printf("MMYY");
        }
        exit (0);
    }
    if(l >= 1 && l <= 12){
        if(f >= 1 && f <= 12){
            printf("AMBIGUOUS");
        }else{
            printf("YYMM");
        }
        exit (0);
    }
    printf("NA");




}