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//~ while (clock()<=69*CLOCKS_PER_SEC)
//~ #pragma comment(linker, "/stack:200000000")
#pragma GCC optimize("O3")
//~ #pragma GCC optimize("Ofast")
//~ #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
//~ #pragma GCC optimize("unroll-loops")

#include <bits/stdc++.h>

using namespace std;

using ll=long long;
using ld=long double;
using pii=pair<int, int>;
using pll=pair<ll, ll>;
using vi=vector<int>;
using vll=vector<ll>;

template<class TH> void _dbg(const char *sdbg, TH h){ cerr<<sdbg<<" = "<<h<<endl; }
#ifdef LOCAL
#define _upgrade ios_base::sync_with_stdio(0);
#define debug(...) _dbg(#__VA_ARGS__, __VA_ARGS__);
#else
#define _upgrade ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
#define debug(...) 98;
#define cerr if(0) cout
#endif

#define pb push_back
#define mp make_pair
#define all(x) x.begin(),x.end()
#define sz(x) ((int)(x).size())
#define fi first
#define se second

#define erase_duplicates(x) sort(all(x)), (x).resize(distance((x).begin(), unique(all(x))));

#define watch(x) cout << (#x) << " is " << (x) << endl;

#define pow2(x) ((x)*(x))
#define mod(x, m) ((((x) % (m)) + (m)) % (m))
#define max3(a, b, c) max(a, max(b, c))
#define min3(a, b, c) min(a, min(b, c))

#define REP(i, a, b) for(int i = a; i <= b; ++i)
#define REPV(i, b, a) for(int i = b; i >= a; --i)

const double m_pi = acos(-1.0);
const int int_max = 0x3f3f3f3f;
const int M7 = 1000*1000*1000+7;
const int M9 = 1000*1000*1000+9;

string copy(string x, long long num) {
    if(num<=9LL) {
        if(num == 0) {
            return "";
        }
        if(num == 1) {
            return x;
        }
        if(num == 2 && sz(x) == 2) {
            return x + x;
        }
        if (num <= 9 && sz(x) == 1) {
            return to_string(num) + x;
        }
    }

    vector<string> add;

    while(num > 0) {
        if(num%9 == 0) {
            add.pb("");
        } else if (num%9 == 1) {
            add.pb(x);
        } else {
            if(sz(x) == 1)add.pb("" + to_string(num%9) + x);
            else add.pb("" + to_string(num%9) + "[" + x + "]");
        }
        num/=9;
    }
    string result = "";
    REPV(i, sz(add)-1, 0) {
        if(sz(result)) {
            if(sz(result) == 1) {
                result = "9" + result;
            } else {
                result = "9[" + result + "]";
            }
        }
        result += add[i];
    }
    return result;
}

string triangle(long long m) {
    string result = "";
    if (m == 0) return result;
    if(m%2==1) {
        result += copy("D", m) + "F";
        result += copy("BF", m-1);
    }

    long long edge = m/2;
    if(edge == 0) return result;

    string drawPara = copy("DF", edge);
    drawPara += "D";
    drawPara += copy("B", edge);
    drawPara = copy(drawPara, edge);

    string moveZigZag = "F" + copy("BF", edge-1);
    result += drawPara;
    result += copy("D", edge);
    result += copy(moveZigZag + triangle(edge - 1), 2);

    return result;
}

int main() {
    _upgrade
    mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
    cout<<fixed<<setprecision(15);

    long long n;
    cin>>n;

    string result = copy("B", n);
    result += triangle(n);

    cout << result << "\n";



    return 0;
}




/*
    __builtin_popcount count total set bits on a given integer
    (use __builtin_popcountll for long long).


*/