#include <iostream>
int main(){
    using namespace std;
    typedef pair<int,char> talls;
    talls h[3]={{0,'A'},{0,'B'},{0,'C'}};
    for(int i=0;i<3;i++)cin >> h[i].first;

    bool done;
    do{
        done=true;
        for(int k=0;k<2;k++){
            if(h[k].first<h[k+1].first){
                talls tmph=h[k];h[k]=h[k+1];h[k+1]=tmph;
                done=false;
            }
        }
    }while(!done);
    
    for(int i=0;i<3;i++){
        cout << h[i].second << endl;
    }
    return 0;
}