#include <iostream>
#include <iomanip>
#include <cassert>
#include <vector>
#include <algorithm>
#include <utility>
#include <numeric>
#include <tuple>
#include <ranges>
namespace ranges = std::ranges;
namespace views = std::views;
// #include "Src/Number/IntegerDivision.hpp"
// #include "Src/Utility/BinarySearch.hpp"
// #include "Src/Sequence/CompressedSequence.hpp"
// #include "Src/Sequence/RunLengthEncoding.hpp"
// #include "Src/Algebra/Group/AdditiveGroup.hpp"
// #include "Src/DataStructure/FenwickTree/FenwickTree.hpp"
// #include "Src/DataStructure/SegmentTree/SegmentTree.hpp"
// #include "Src/DataStructure/DisjointSetUnion/DisjointSetUnion.hpp"
// using namespace zawa;
// #include "atcoder/modint"
// using mint = atcoder::modint998244353;
using namespace std;
int N, A[100];
bool is_subset(int s, int S) {
    return (s | (S ^ s)) == S;
}
int main() {
    cin.tie(0);
    cout.tie(0);
    ios::sync_with_stdio(0);
    cin >> N;
    for (int i = 0 ; i < N ; i++) cin >> A[i];
    int ans = 0;
    string S(N, 'W');
    for (int b = 0 ; b < (1 << 12) ; b++) {
        int W = 0, B = 0;
        bool ok = true;
        string T;
        const int msk = b ^ ((1 << 12) - 1);
        for (int i = 0 ; i < N ; i++) {
            if (is_subset(A[i], b)) {
                W |= A[i];
                T += 'W';
            }
            else if (is_subset(A[i], msk)) {
                B |= A[i];
                T += 'B';
            }
            else ok = false;
        }
        if (ok and ans < W * B) {
            assert((W & B) == 0);
            ans = W * B;
            S = T;
        }
    }
    cout << ans << '\n' << S << '\n';
}