#include <algorithm>
#include <atcoder/all>
#include <bitset>
#include <cassert>
#include <cmath>
#include <ctime>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
using namespace std;
using namespace atcoder;
typedef long long ll;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define repr(i, n) for (int i = (int)(n) - 1; i >= 0; i--)
#define repk(i, k, n) for (int i = k; i < (int)(n); i++)
#define all(v) v.begin(), v.end()
#define mod1 1000000007
#define mod2 998244353
#define mod3 100000007
#define vi vector<int>
#define vs vector<string>
#define vc vector<char>
#define vl vector<ll>
#define vb vector<bool>
#define vvi vector<vector<int>>
#define vvc vector<vector<char>>
#define vvl vector<vector<ll>>
#define vvb vector<vector<bool>>
#define vvvi vector<vector<vector<int>>>
#define vvvl vector<vector<vector<ll>>>
#define pii pair<int, int>
#define pil pair<int, ll>
#define pli pair<ll, int>
#define pll pair<ll, ll>
#define vpii vector<pair<int, int>>
#define vpll vector<pair<ll, ll>>
#define vvpii vector<vector<pair<int, int>>>
#define vvpll vector<vector<pair<ll, ll>>>

template <typename T>
void debug(T e) {
    cerr << e << endl;
}

template <typename T>
void debug(vector<T> &v) {
    rep(i, v.size()) { cerr << v[i] << " "; }
    cerr << endl;
}

template <typename T>
void debug(vector<vector<T>> &v) {
    rep(i, v.size()) {
        rep(j, v[i].size()) { cerr << v[i][j] << " "; }
        cerr << endl;
    }
}

template <typename T>
void debug(vector<pair<T, T>> &v) {
    rep(i, v.size()) { cerr << v[i].first << " " << v[i].second << endl; }
}

template <typename T>
void debug(set<T> &st) {
    for (auto itr = st.begin(); itr != st.end(); itr++) {
        cerr << *itr << " ";
    }
    cerr << endl;
}

template <typename T>
void debug(multiset<T> &ms) {
    for (auto itr = ms.begin(); itr != ms.end(); itr++) {
        cerr << *itr << " ";
    }
    cerr << endl;
}

template <typename T>
void debug(map<T, T> &mp) {
    for (auto itr = mp.begin(); itr != mp.end(); itr++) {
        cerr << itr->first << " " << itr->second << endl;
    }
}

void debug_out() { cerr << endl; }

template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << H << " ";
    debug_out(T...);
}

using mint = modint1000000007;

void debug_mint1(vector<mint> &vec) {
    for (int i = 0; i < vec.size(); i++) {
        cerr << vec[i].val() << " ";
    }
    cerr << endl;
}

void debug_mint2(vector<vector<mint>> &vec) {
    for (int i = 0; i < vec.size(); i++) {
        for (int j = 0; j < vec[i].size(); j++) {
            cerr << vec[i][j].val() << " ";
        }
        cerr << endl;
    }
}

vector<ll> n_adic(ll i, ll n, ll N) {
    ll x = 1;
    rep(j, N) { x *= n; }
    vector<ll> vec(N);
    rep(j, N) {
        x /= n;
        vec[j] = i / x;
        i -= x * vec[j];
    }
    return vec;
}

int main() {
    ll N;
    cin >> N;
    vector<ll> A(N);
    for (ll i = 0; i < N; i++) {
        cin >> A[i];
    }
    ll now = 1;
    for (ll i = 0; i < 12; i++) {
        now *= 3;
    }
    vector<vector<ll>> pows(now, vector<ll>(12));
    for (ll i = 0; i < now; i++) {
        vector<ll> tri = n_adic(i, 3, 12);
        for (ll j = 0; j < 12; j++) {
            pows[i][j] = tri[j];
        }
    }
    vector<ll> pow_3(13);
    pow_3[0] = 1;
    for (ll i = 0; i < 12; i++) {
        pow_3[i + 1] = pow_3[i] * 3;
    }
    vector<vector<bool>> dp(N + 1, vector<bool>(now, false));
    dp[0][0] = true;
    for (ll i = 0; i < N; i++) {
        for (ll j = 0; j < now; j++) {
            if (!dp[i][j]) {
                continue;
            }
            bool black = true;
            bool white = true;
            for (ll k = 0; k < 12; k++) {
                if (!((A[i] >> k) & 1)) {
                    continue;
                }
                if (pows[j][k] == 2) {
                    black = false;
                }
                if (pows[j][k] == 1) {
                    white = false;
                }
            }
            if (black) {
                ll next = j;
                for (ll k = 0; k < 12; k++) {
                    if ((A[i] >> k) & 1) {
                        if (pows[j][k] == 0) {
                            next += pow_3[11 - k];
                        }
                    }
                }
                dp[i + 1][next] = true;
            }
            if (white) {
                ll next = j;
                for (ll k = 0; k < 12; k++) {
                    if ((A[i] >> k) & 1) {
                        if (pows[j][k] == 0) {
                            next += pow_3[11 - k] * 2;
                        }
                    }
                }
                dp[i + 1][next] = true;
            }
        }
    }
    ll ans = 0;
    ll ans_j = -1;
    for (ll j = 0; j < now; j++) {
        ll b = 0;
        ll w = 0;
        if (!dp[N][j]) {
            continue;
        }
        // debug(j);
        for (ll k = 0; k < 12; k++) {
            if (pows[j][k] == 1) {
                b += (1 << k);
            } else if (pows[j][k] == 2) {
                w += (1 << k);
            }
        }
        if (ans < b * w) {
            ans = b * w;
            ans_j = j;
        }
    }
    cout << ans << endl;
    if (ans == 0) {
        string ans_s = "";
        for (ll i = 0; i < N; i++) {
            ans_s += 'B';
        }
        cout << ans_s << endl;
    }
    ll now_j = ans_j;
    vector<char> s(N);
    for (ll i = N - 1; i >= 0; i--) {
        for (ll j = 0; j < now; j++) {
            if (!dp[i][j]) {
                continue;
            }
            bool black = true;
            bool white = true;
            for (ll k = 0; k < 12; k++) {
                if (!((A[i] >> k) & 1)) {
                    continue;
                }
                if (pows[j][k] == 2) {
                    black = false;
                }
                if (pows[j][k] == 1) {
                    white = false;
                }
            }
            if (black) {
                ll next = j;
                for (ll k = 0; k < 12; k++) {
                    if ((A[i] >> k) & 1) {
                        if (pows[j][k] == 0) {
                            next += pow_3[11 - k];
                        }
                    }
                }
                if (next == now_j) {
                    now_j = j;
                    s[i] = 'B';
                    break;
                }
            }
            if (white) {
                ll next = j;
                for (ll k = 0; k < 12; k++) {
                    if ((A[i] >> k) & 1) {
                        if (pows[j][k] == 0) {
                            next += pow_3[11 - k] * 2;
                        }
                    }
                }
                if (next == now_j) {
                    now_j = j;
                    s[i] = 'W';
                    break;
                }
            }
        }
    }
    for (ll i = 0; i < N; i++) {
        cout << s[i];
    }
    cout << endl;
}