#include <bits/stdc++.h>

using namespace std;

struct Node {
    char level;
    int cnt;
    //实现了<运算符重载
    bool operator<(const Node &c) const {
        return cnt > c.cnt;
    }
};
priority_queue<Node> q;


/**
 测试用例：
 10 13 14 5
 */
int main() {
    for (int i = 1; i <= 4; i++) {
        Node pic;
        cin >> pic.cnt;
        pic.level = 'A' + i - 1;
        q.push(pic);
    }
    while (q.size()>2) {
        cout << q.top().level << endl;
        q.pop();

        cout << q.top().level << endl;
        q.pop();

        cout<<"---------------";
    }
    return 0;
}