#include <bits/stdc++.h>
// #include <boost/multiprecision/cpp_int.hpp>
using namespace std;
// using bigint = boost::multiprecision::cpp_int;

template <typename T> using min_priority_queue = priority_queue<T,vector<T>,greater<T>>;

random_device seed_gen;
mt19937 engine(seed_gen());

int64_t get_time_ns(){
    struct::timespec t;
    clock_gettime(CLOCK_MONOTONIC, &t);
    return t.tv_sec * int64_t(1'000'000'000) + t.tv_nsec;
}

int main() {
    int n = 3;
    vector<pair<int,char>> V(n);
    for(int i = 0; i < n; i++) {
        auto &[h, c] = V[i];
        cin >> h;
        c = 'A' + i;
    }

    sort(V.begin(), V.end());
    reverse(V.begin(), V.end());

    for(auto [h, c] : V) {
        cout << c << endl;
    }
    return 0;
}