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#include <bits/stdc++.h>
#ifdef LOC
#include "debuglib.h"
#else
#define deb(...)
#define DBP(...)
#endif
using namespace std;
using   ll         = long long;
using   vi         = vector<int>;
using   pii        = pair<int, int>;
#define pb           push_back
#define mp           make_pair
#define x            first
#define y            second
#define rep(i, b, e) for (int i = (b); i < (e); i++)
#define each(a, x)   for (auto& a : (x))
#define all(x)       (x).begin(), (x).end()
#define sz(x)        int((x).size())

void step(string& out, const string& s, ll repeat) {
	if (s.empty() || repeat == 0) return;
	if (repeat == 1) {
		out += s;
	} else if (repeat > 9) {
		string tmp;
		step(tmp, s, repeat/9);
		step(out, tmp, 9);
		step(out, s, repeat%9);
	} else {
		out.pb(char(repeat+'0'));
		if (sz(s) > 1) out.pb('[');
		out += s;
		if (sz(s) > 1) out.pb(']');
	}
}

void withoutLeftSide(string& out, ll n) {
	if (n < 3) {
		for (ll i = n; i > 0; i--) {
			step(out, "A", i);
			step(out, "EC", i-1);
			step(out, "E", 1);
		}
	} else if (n%2 == 0) {
		step(out, "A", n);
		step(out, "EC", n-1);
		step(out, "E", 1);
		withoutLeftSide(out, n-1);
	} else {
		ll k = n/2-1;
		step(out, "AF", 1);

		string rec;
		withoutLeftSide(rec, k);
		step(out, rec, 2);

		step(out, "C", k*2);
		step(out, "BF", k);

		string stripe;
		step(stripe, "FD", k-1);
		step(stripe, "F", 1);
		step(stripe, "B", k);
		step(out, stripe, k);

		step(out, "FD", k*2);
		step(out, "F", 1);
		step(out, "B", k*2+1);
		step(out, "D", k+1);

		step(out, "BF", k+1);
		step(out, "B", 1);
		step(out, "D", k*2+2);
		step(out, "EA", k*2+2);
		step(out, "E", 1);
	}
}

string solve(ll n) {
	string out;
	withoutLeftSide(out, n);
	step(out, "C", n);
	return out;
}

int main() {
	cin.sync_with_stdio(0); cin.tie(0);
	cout << fixed << setprecision(10);
	ll n; cin >> n;
	string ans = solve(n);
#ifdef LOC
	deb(n, sz(ans));
	assert(sz(ans) <= 150000);
#endif
	cout << ans << '\n';
	cout << flush; _Exit(0);
}