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(int argc, const char * argv[]) {
    
    
    char S[50] = {};
    int flagA = 0;
    int flagB = 0;
    scanf("%s",S);

    
    if (S[2] == '0' || (S[2] == '1') & (S[3] == '0' || S[3] == '1' || S[3] == '2')) {
        if (S[2] == '0' & S[3] == '0') {
            printf("NA");
            exit(0);
        }
        flagA++;
    }
    if (S[0] == '0' || (S[0] == '1') & (S[1] == '0' || S[1] == '1' || S[1] == '2')) {
        if (S[0] == '0' & S[1] == '0') {
            printf("NA");
            exit(0);
        }
        flagB++;
    }
    
    if (flagA == 1 & flagB == 1) {
        printf("AMBIGUOUS");
    }else if(flagA == 1 && flagB == 0){
        printf("YYMM");
    }else if(flagA == 0 && flagB == 1){
        printf("MMYY");
    }else{
        printf("NA");
    }
}