#include<bits/stdc++.h> using namespace std; int c,d,e; int main(){ int a; cin>>a; for(int i=0;i<a;i++){ int b; cin>>b; if(b==1)c++; if(b==2)d++; if(b==3)e++; } for(int i=0;1<1;i++){ if(c==d&&c>e)cout<<"NONE";break; if(c==e&&c>d)cout<<"NONE";break; if(e==d&&e>c)cout<<"NONE";break; if(c>d&&c>e)cout<<"A";break; if(d>e&&d>e)cout<<"B";break; if(e>c&&e>d)cout<<"C";break; } return 0; }