#include<bits/stdc++.h> using namespace std; int main(){ string s,s1,s2; cin>>s; s1.insert(s1.begin(),1,s[0]); s1.insert(1,1,s[1]); s2.insert(s2.begin(),1,s[2]); s2.insert(1,1,s[3]); if(s1>="01"&&s1<="12"){ if(s2>="01"&&s2<="12"){ cout<<"AMBIGUOUS"; } else{ cout<<"MMYY"; } }else if(s2>="01"&&s2<="12"){ cout<<"YYMM"; } else{ cout<<"NA"; } return 0; }