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 (Clang 3.8.0) (judge verdict: Accepted)

#include <stdio.h>


// YYMM 00 ~ 99 && 01 ~ 12
// MMYY 01 ~ 12 && 00 ~ 99
int main(void) {
    int a,b,c,d,s,no1,no2;
    a = b = c = d = no1 = no2 = 0;
    scanf("%d",&s);
    a = s % 10;
    s = s / 10;
    b = s % 10;
    s = s / 10;
    c = s % 10;
    s = s / 10;
    d = s % 10;
    no1 = d * 10 + c;
    no2 = b * 10 + a;
    if ((no1 > 12 && no2 > 12) || (no1 == 0 && no2 == 0) || (no1 == 0 && no2 > 12) || (no2 == 0 && no1 > 12)){
        printf("NA");
    }else if ((no1 == 0 && no2 != 0)|| (no1 > 12 && no2 != 0)){
        printf("YYMM");
    }else if ((no2 == 0 && no1 != 0)|| (no2 > 12 && no1 != 0 )){
        printf("MMYY");
    }else{
        printf("AMBIGUOUS");
    }
return 0;
}