#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++; } if(c==d&&c>=e)cout<<"NONE"; if(c==e&&c>=d)cout<<"NONE"; if(e==d&&e>=c)cout<<"NONE"; if(c>d&&c>e)cout<<"A"; if(d>e&&d>e)cout<<"B"; if(e>c&&e>d)cout<<"C"; return 0; }