#include <algorithm>
#include <iostream>
using namespace std;
int main(){
struct brother{
	char name;
	int high;
};
brother great[3];
cin>>great[0].high>>great[1].high>>great[2].high;
great[0].name='A';
great[1].name='B';
great[2].name='C';
sort(great,great+3,[](const brother& x, const brother& y){return x.high>y.high;});
cout<<great[0].name<<"\n"<<great[1].name<<"\n"<<great[2].name<<"\n";
return 0;
}