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>

int main(){
    char YM[4];
    int first,last;
    int first1,first2;
    int last1,last2;
    scanf("%s",&YM);
    first1 = ( YM[0] - '0' ) * 10;
    first2 = ( YM[1] - '0' );
    last1 = ( YM[2] - '0' ) * 10;
    last2 = ( YM[3] - '0' );
    first = first1 + first2;
    last = last1 + last2;
    if( ((first >= 1) && (first <= 12)) && ((last >= 0) && (last <= 99)) && ((first >= 0) && (first <= 99)) && ((last >= 1) && (last <= 12))){
        printf("AMBIGUOUS\n");
    }else if( ((first >= 1) && (first <= 12)) && ((last >= 0) && (last <= 99)) ){
        printf("MMYY\n");
    }else if( ((first >= 0) && (first <= 99)) && ((last >= 1) && (last <= 12)) ){
        printf("YYMM\n");
    }else{
        printf("NA\n");
    }
    //printf("%d %d",first,last);
    return 0;
}