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>
#include <stdlib.h>

int main(void){
    char s[4];

    scanf("%s",s);
    if(s[0] == '0'){
        if(s[1] == '0'){
            printf("NA");
        }else{
            if(s[2] == '0'){
                if(s[3] != '0') printf("AMBIGUOUS");
                else printf("NA");
            }else if(s[2] == '1'){
                if((int)s[3] <= 50){
                    printf("AMBIGUOUS");
                }else{
                    printf("MMYY");
                }
            }else{
                printf("MMYY");
            }
        }    
    }else if(s[0] == '1'){
        if((int)(s[1]) <= 50){
            if(s[2] == '0'){
                if(s[3] != '0') printf("AMBIGUOUS");
                else printf("NA");
            }else if(s[2] == '1' && (int)(s[3]) <= 50){
                printf("AMBIGUOUS");
            }else{
                printf("MMYY");
            }
        }else{
            if(s[2] == '0'){
                if(s[3] != '0') printf("YYMM");
                else printf("NA");
            }else if(s[2] == '1' && (int)(s[3]) <= 50){
                printf("YYMM");
            }else{
                printf("NA");
            }
        }
    }else{
        if(s[2] == '0'){
            if(s[3] != '0') printf("YYMM");
            else printf("NA");
        }else if(s[2] == '1' && (int)(s[3]) <= 50){
            printf("YYMM");
        }else{
            printf("NA");
        }    
    }
    
}