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 Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

/*
String[]の初期化、整数の型がlongになっているか
関数（splitとかcontainsとか）内では"+"とかは正規表現となされるので"\\+"とする
配列のコピーはarr1=arr.clone()
HashSet<>[]はおのおの初期化した？？？？？
負の数の割り算は絶対値が小さいほうに切り捨てられるex.-1/2=0ので、ある値>kみたいな式だとバグらせやすいので注意
ある値>=kとして、切り上げた値をとるべき
toLowerCase()はアルファベット以外に対して行ってもエラーにはならない
ArrayDequeではpopとpushはStackと同じ操作になる
//import static java.lang.System.*; はしばらく使わなそう(使うとしてもexit(0)のためだけ)←return;でよさそう
最後にout.flush()またはout.close()をするのを忘れずに！
Point2D p2d=new Point2D.Double(d1,d2);
//import static java.lang.System.*;
*/
//入力終了→Ctrl+D
import java.lang.reflect.Array;
import java.net.Inet4Address;
import java.util.*;
import java.io.*;
import java.awt.*;
import java.awt.geom.Point2D;
import static java.lang.Math.*;
public class Main {
    public static void main(String[] $) {
        String s=sc.next(),ans="";
        String left=s.substring(0,2);
        String right=s.substring(2,4);
        int l=Integer.parseInt(left);
        int r=Integer.parseInt(right);
        if(l<13&&r<13){
            ans="AMBIGUOUS";
        }else if(l<13){
            ans="MMYY";
        }else if(r<13){
            ans="YYMM";
        }else {
            ans="NA";
        }
        out.println(ans);
        out.close();
    }

    static boolean nextPermutation(int[] a) {
        int t = a.length - 1;
        int tt = t + 1;
        for (int i = t; i > 0; --i) {
            if (a[i - 1] < a[i]) {
                int swapIndex = Find(a[i - 1], a, i, t);
                int temp = a[swapIndex];
                a[swapIndex] = a[i - 1];
                a[i - 1] = temp;
                Arrays.sort(a, i, tt);
                return true;
            }
        }
        return false;
    }

    static int Find(int dest, int[] a, int s, int e) {
        if (s == e) {
            return s;
        }
        int m = (s + e + 1) / 2;
        return a[m] <= dest ? Find(dest, a, s, m - 1) : Find(dest, a, m, e);
    }

    static class pair {
        long x, y;

        pair(long a, long b) {
            a = x;
            b = y;
        }
    }

    static class Point3D {
        Point3D(int a, int b, int c) {
            a = x;
            b = y;
            c = z;
        }

        int x, y, z;
    }

    static long mod = 1000000007;

    static long power(long x, long n) {
        if (n == 0) return 1;
        if (n % 2 == 0) {
            long e = power(x, n / 2) % mod;
            return (e * e) % mod;
        }
        return (x * power(x, n - 1)) % mod;
    }

    static long gcd(long a, long b) {
        return b == 0 ? a : gcd(b, a % b);
    }

    static class COM {
        static long[] fact;
        static long[] inv;

        static void Init(int n) {
            fact = new long[n];
            inv = new long[n];
            fact[0] = inv[0] = 1;
            for (int i = 1; i < n; i++) {
                fact[i] = (fact[i - 1] * i) % mod;
                inv[i] = power(fact[i], mod - 2);
            }
        }

        static long C(int n, int k) {
            if (k > n) return 0;
            return ((fact[n] * inv[n - k]) % mod * inv[k]) % mod;
        }
    }

    static class UF {
        static int[] d;

        static void Init(int size) {
            d = new int[size];
            for (int i = 0; i < size; i++) {
                d[i] = -1;
            }
        }

        static boolean unite(int x, int y) {
            x = find(x);
            y = find(y);
            if (x == y) return false;
            if (d[x] > d[y]) {
                int t = d[y];
                d[y] = d[x];
                d[x] = t;
            }
            d[x] += d[y];
            d[y] = x;
            return true;
        }

        static boolean same(int x, int y) {
            return find(x) == find(y);
        }

        static int find(int k) {
            return d[k] < 0 ? k : (d[k] = find(d[k]));
        }

        static int size(int k) {
            return -d[find(k)];
        }
    }

    static class ST {
        //0-indexed
        //親:(n-1)/2,子:2*n+1,2*n+2
        //i番目のindex→n+i-1
        static long INF = 0;
        static int n = 131072;
        static long[] d = new long[n * 2 - 1];

        static void Init() {
            for (int i = 0; i < n * 2 - 1; i++) d[i] = INF;
        }

        //i番目の要素をxに変更（この関数はnが2の累乗でないと機能しない）
        static void update(int i, long x) {
            i += n - 1;
            d[i] = x;
            while (i > 0) {
                i = (i - 1) / 2;
                d[i] = gcd(d[i * 2 + 1], d[i * 2 + 2]);
            }
        }

        //[a,b)の最小値,l,rにはノードkに対応付く区間を与える
        static long query(int a, int b, int k, int l, int r) {
            if (r <= a || b <= l) return INF;
            if (a <= l && r <= b) return d[k];
            long vl = query(a, b, k * 2 + 1, l, (l + r) / 2);
            long vr = query(a, b, k * 2 + 2, (l + r) / 2, r);
            return gcd(vl, vr);
        }
        //ex.[a,b)のmin→query(a,b,0,0,ST.n)
    }

    static void WF(long[][] d, int[] a, int[] b, long[] c) {
        int n = a.length;
        long INF = 100000000000l;
        for (int i = 0; i < n; i++) {
            for (int j = i; j < n; j++) {
                d[i][j] = d[j][i] = INF;
            }
        }
        for (int i = 0; i < n; i++) {
            d[a[i]][b[i]] = d[b[i]][a[i]] = c[i];
        }
        for (int k = 0; k < n; k++) {
            for (int i = 0; i < n; i++) {
                for (int j = 0; j < n; j++) {
                    d[i][j] = d[i][j] > d[i][k] + d[k][j] ? d[i][k] + d[k][j] : d[i][j];
                }
            }
        }
    }

    static PrintWriter out = new PrintWriter(System.out);

    static class sc {
        static Scanner s = new Scanner(System.in);

        static String next() {
            return s.next();
        }

        static String nextLine() {
            return s.nextLine();
        }

        static int nextInt() {
            return Integer.parseInt(s.next());
        }

        static long nextLong() {
            return Long.parseLong(s.next());
        }

        static double nextDouble() {
            return Double.parseDouble(s.next());
        }

        static boolean hasNext() {
            return s.hasNext();
        }
    }

}