#include<bits/stdc++.h> using namespace std; int a[100]; int A,B,C; int main(){ int n;cin>>n; for(int i=0;i<n;i++){ cin>>a[i]; if(a[i]==1)A++; else if(a[i]==2)B++; else C++; } if(A!=B and A!=C and B!=C){ if(A>B and A>C)cout<<"A"; if(B>A and B>C)cout<<"B"; if(C>B and C>A)cout<<"C"; }else{ cout<<"NONE"; } return 0; }