#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,char> P;
#define yn {puts("Yes");}else{puts("No");}
#define MAX_N 200005

int main() {
    vector<pair<int,char>> v;
    int a,b,c;
    cin >> a >> b >> c;
    v.push_back(P(a,'A'));
    v.push_back(P(b,'B'));
    v.push_back(P(c,'C'));
    sort(v.begin(), v.end(), greater<P>());
    rep(i,3)cout << v[i].second << endl;
    return 0;
}