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#include <bits/stdc++.h>

using namespace std;

typedef unsigned uint;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ldbl;
typedef pair<int, int> pii;
typedef pair<uint, uint> puu;
typedef pair<ll, ll> pll;
typedef pair<ull, ull> pull;
typedef pair<double, double> pdd;
typedef vector<int> vi;
typedef vector<uint> vu;
typedef vector<ll> vll;
typedef vector<ull> vull;
typedef vector<pii> vpii;
typedef vector<puu> vpuu;
typedef vector<pll> vpll;
typedef vector<pull> vpull;
typedef vector<string> vstr;
typedef vector<double> vdbl;
typedef vector<ldbl> vldbl;
#define pb push_back
#define ppb pop_back
#define pfr push_front
#define ppfr pop_front
#define emp emplace
#define empb emplace_back
#define be begin
#define rbe rbegin
#define all(x) (x).be(), (x).end()
#define rall(x) (x).rbe(), (x).rend()
#define fir first
#define sec second
#define mkp make_pair
#define brif(cond) if (cond) break
#define ctif(cond) if (cond) continue
#define retif(cond) if (cond) return
void canhazfast() {ios_base::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);}
template<typename T> T gcd(T a, T b) {return b ? gcd(b, a%b) : a;}
template<typename T> T extgcd(T a, T b, T &x, T &y)
{
    T x0 = 1, y0 = 0, x1 = 0, y1 = 1;
    while (b) {
        T q = a/b; a %= b; swap(a, b);
        x0 -= q*x1; swap(x0, x1);
        y0 -= q*y1; swap(y0, y1);
    }
    x = x0; y = y0; return a;
}
int ctz(uint x) {return __builtin_ctz(x);}
int ctzll(ull x) {return __builtin_ctzll(x);}
int clz(uint x) {return __builtin_clz(x);}
int clzll(ull x) {return __builtin_clzll(x);}
int popcnt(uint x) {return __builtin_popcount(x);}
int popcntll(ull x) {return __builtin_popcountll(x);}
int bsr(uint x) {return 31^clz(x);}
int bsrll(ull x) {return 63^clzll(x);}

/// CCW
string closed_tri(ll n); /// V: BR -> TL, E: all
string open_tri(ll n); /// V: BR -> TL, E: TR
string rect(ll w, ll h); /// V: TL -> BL, E: T, L, R

void append_small_repeat(string &dst, const string &src, int k)
{
    switch (k) {
    case 0:
        return;
    case 1:
        dst += src;
        return;
    case 2:
        if (src.size() == 2) {
            dst += src;
            dst += src;
            return;
        }
    }
    dst += k+'0';
    if (src.size() > 1) {
        dst += '[';
        dst += src;
        dst += ']';
    } else {
        dst += src[0];
    }
}

string repeat(const string &s, ll n)
{
    string res;
    int depth = 0;
    while (n > 9) {
        int r = 0, d = 0;
        for (int i = 9; i >= 2; --i) {
            ll q = n/i;
            r = n%i;
            if (r == 0) {
                n = q;
                d = i;
                break;
            }
        }
        if (d == 0) {
            d = 9;
            r = n%9;
            n /= 9;
        }
        append_small_repeat(res, s, r);
        res += d+'0';
        res += '[';
        ++depth;
    }
    append_small_repeat(res, s, n);
    for (int i = 0; i < depth; ++i) res += ']';
    return res;
}

string closed_tri(ll n)
{
    retif(n == 1) "ECA";
    retif(n == 3) "3ECACEC2ACECEC3A";
    ///int d = min(n, 2LL);
    constexpr int d = 2;
    ll q = n/d, r = n%d;
    string res = repeat(open_tri(q), d);
    if (r) {
        res += open_tri(r);
        res += repeat("C", r);
        res += rect(r, q);
    } else {
        res += repeat("C", q);
    }
    for (int i = 1; i < d; ++i) res += rect(i*q+r, q);
    ///res += rect(q+r, q);
    res += repeat("A", n);
    return res;
}

string open_tri(ll n)
{
    retif(n == 1) "E";
    retif(n == 2) "ECEAE";
    return 'E'+closed_tri(n-2)+repeat("CE", n-1)+repeat("AE", n-1);
}

string rect_rmaj(ll w, ll h)
{
    string row = repeat("A", w)+repeat("CE", w)+'C';
    string alt_row = repeat("A", w)+repeat("CE", w/2)+'C'+repeat("EC", w-w/2);
    if (alt_row.size() < row.size()) swap(row, alt_row);
    return repeat(row, h);
}

string rect_cmaj(ll w, ll h)
{
    string col = repeat("EA", h-1)+'E';
    ///string alt_col = ...
    col += repeat("C", h);
    return repeat("A", w)+repeat("C", h)+repeat(col, w);
}

string rect(ll w, ll h)
{
    string r = rect_rmaj(w, h);
    string c = rect_cmaj(w, h);
    return c.size() < r.size() ? c : r;
}

int main()
{
    canhazfast();

    ll n;
    string ans;

    cin >> n;
    ans = closed_tri(n);
    cout << ans << '\n';
    //cerr << "len = " << ans.size() << '\n';

    /**mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
    uniform_int_distribution<ll> dist(1LL, 1000000000000000000LL);
    constexpr int iters = 2e5;
    size_t lmax = 0;
    for (int i = 0; i < iters; ++i) {
        n = dist(rng);
        ans = closed_tri(n);
        size_t len = ans.size();
        if (lmax < len) {
            lmax = len;
            cerr << "lmax = " << lmax << '\n';
        }
        if ((i+1)%10000 == 0) cerr << i+1 << " iters\n";
    }**/

    return 0;
}