#include<bits/stdc++.h>
using namespace std;
using ll = long long;

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

#define FOR(i,a,b) for(ll i=(a);i<(b);++i)
#define ALL(v) (v).begin(), (v).end()
#define p(s) cout<<(s)<<endl
#define p2(s, t) cout << (s) << " " << (t) << endl
#define br() p("")
#define pn(s) cout << (#s) << " " << (s) << endl
#define p_yes() p("Yes")
#define p_no() p("No")

typedef pair<ll, char> P;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    vector<P> A;
    FOR(i, 0, 3){
        ll h; cin >> h;
        char name = 'A' + i;
        A.push_back(P(h, name));
    }
    sort(ALL(A), greater<P>());
    
    for(auto pa : A){
        p(pa.second);
    }
    
    return 0;
}