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: Wrong Answer)

#include<stdio.h>
int main(void){
    int a[4], b;
    scanf("%d", &b);
    a[3]=b%10;
    a[2]=b%100 - a[3];
    a[1]=b%1000 - 10*a[2]-a[3];
    a[0]=b-100*a[1]-10*a[2]-a[3];
    if((a[0]==0&&(a[1]<=9&&a[1]>=1))||(a[0]==1&&(a[1]<=2&&a[1]>=0))){
        if((a[2]==0&&(a[3]<=9&&a[3]>=1))||(a[2]==1&&(a[3]<=2&&a[3]>=0))){
            printf("AMBIGUOUS");
        }else{
            printf("MMYY");
        }
    }else{
        if((a[2]==0&&(a[3]<=9&&a[3]>=1))||(a[2]==1&&(a[3]<=2&&a[3]>=0))){
            printf("YYMM");
        }else{
            printf("AMBIGUOUS");
        }
    }
    return 0;
}