#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll mod = 1e9 + 7;
const int N = 200005;
const int INF = 0x3f3f3f3f;
int a[N];
int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n;
    cin >> n;
    int mx = 0;
    for (int i = 0; i < n; i++) {
        cin >> a[i];
        mx = max(mx, a[i]);
    }
    int k = __lg(mx) + 1;
    int max1 = (1 << k) - 1;
    ll ans = 0;
    int u = 0;
    for (int mask = 0; mask <= max1; mask++) {
        ll m1 = 0, m2 = 0;
        bool ok = 1;
        for (int i = 0; i < n; i++) {
            bool fw = !(a[i] & (max1 ^ mask));
            bool fb = !(a[i] & mask);
            if (!fw && !fb) {
                ok = 0;
                break;
            }
            if (fw) {
                m1 |= a[i];
            } else {
                m2 |= a[i];
            }
        }
        if (!ok) continue;
        if (m1 * m2 > ans) {
            ans = m1 * m2;
            u = mask;
        }
    }
    string res;
    ll m1 = 0, m2 = 0;
    for (int i = 0; i < n; i++) {
        bool fw = !(a[i] & (max1 ^ u));
        if (fw) {
            res.push_back('B');
            m1 |= a[i];
        } else {
            res.push_back('W');
            m2 |= a[i];
        }
    }
    cout << ans << "\n";
    cout << res << "\n";
    return 0;
}