#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define F first
#define S second
#define pii pair<int, int>
#define eb emplace_back
#define all(v) v.begin(), v.end()
#define rep(i, n) for (int i = 0; i < n; ++i)
#define rep3(i, l, n) for (int i = l; i < n; ++i)
#define chmax(a, b) a = (a >= b ? a : b)
#define chmin(a, b) a = (a <= b ? a : b)
#define out(a) cout << (a) << endl
#define outa(a, n) rep(_, n) cout << a[_] << " "; cout << endl
#define SZ(v) (int)v.size()
#define inf (int)(1e9+7)
#define abs(x) (x >= 0 ? x : -(x))

bool comp(pair<char, int> a, pair<char, int> b) {
    return a.S > b.S;
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    pair<char, int> a[3];
    rep(i, 3) a[i].F = 'a' + i;
    rep(i, 3) cin >> a[i].S;
    sort(a, a + 3, comp);
    rep(i, 3) out((char)toupper(a[i].F));
}