#include<iostream>

using namespace std;

int main(){
    int a,b,c;
    
    cin>>a>>b>>c;
    if(a>b && a>c) cout<<"A"<<endl;
    else if(b>a && b>c) cout<<"B"<<endl;
    else if(c>a && c>b) cout<<"C"<<endl;
    
    return 0;
}
