#include<cstdio>
#include<cstdlib>
#include<algorithm>
#include<iostream>
#include<queue>
#include<vector>
#include <bitset>
#include <cmath>
#include <limits>
#include <iostream>
using namespace std;
#define INF 100000
#define MAX 100000
#define MOD 1000000007
typedef long long ll;
typedef pair<int,int> P;
typedef pair< pair<int,int>, int> p; 
#define bit(n,k) ((n>>k)&1) /*nのk bit目*/
#define rad_to_deg(rad) (((rad)/2/M_PI)*360)

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