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++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define REP(i, n) for(ll i=0; i<(ll)n; i++)
#define REPR(i, n) for(ll i=(ll)n-1; i>=0; i--)
#define FOR(i, m, n) for(ll i=(ll)m; i<(ll)n; i++)
#define FORR(i, m, n) for(ll i=(ll)m-1; i>=(ll)n; i--)
#define ALL(x) (x).begin(), (x).end()
#define ASC(v) sort(ALL(v));
#define DESC(v) sort(ALL(v), greater<int>());
#define UNIQ(a) sort(ALL(a));(a).resize(unique(ALL(a)) - a.begin());
#define PRINTD(x, d) cout << fixed << setprecision(d) << x << "\n";
#define DEBUG(x) cout<<#x<<": "<<x<<"\n"
const double PI = acos(-1);
ll lcm(ll a, ll b) { return a / __gcd(a, b) * b; }
bool isprime(int x){ int i; if(x<2)return 0; else if(x==2) return 1; if(x%2==0) return 0; for(i=3; i*i<=x; i+=2) if(x%i==0) return 0; return 1; }
int digsum(int n) { int r=0; while(n>0) { r+=n%10; n/=10; } return r; }
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a = b; return 1; } return 0; }
void rcmb(ll *x,ll s,ll r,function<void(ll *)>f){if(r==0){f(x);}else{if(s<0)return;rcmb(x,s-1,r,f);x[r-1]=s;rcmb(x,s-1,r-1,f);}}
void cmb(ll n,ll k,function<void(ll *)>f){ll x[k];rcmb(x,n-1,k,f);}
void prm(ll n,function<void(ll *)>f){ll x[n];for(ll i=0;i<n;i++)x[i]=i;do{f(x);}while(next_permutation(x,x+n));}
void prm(ll n,ll k,function<void(ll *)>f){cmb(n,k,[&](ll *c){prm(k,[&](ll *p){ll x[k];for(ll i=0;i<k;i++){x[i]=c[p[i]];}f(x);});});}
// prm(4, 2, [](ll *x){ cout << x[0] << "," << x[1] << "\n"; });


void solve(string S){
	string s1 = S.substr(0, 2);
	string s2 = S.substr(2, 2);
	ll n1 = stoi(s1);
	ll n2 = stoi(s2);
	string res = "NA";
	if (n1==0||n2==0) res = "NA";
	else if (n1<=12 && n2<=12) res = "AMBIGUOUS";
	else if (n1<=12) res = "MMYY";
	else if (n2<=12) res = "YYMM";
	cout << res << "\n";
}

int main(){
	string S;
	cin >> S;
    solve(S);
    return 0;
}