#include <bits/stdc++.h>

using namespace std;

typedef pair<int, int> pii;
typedef long long ll;
const int N = 2000086, MOD = 1e9 + 7, INF = 0x3f3f3f3f;
ll res;
int n, m, cnt, w[N];

char ans[N], s[N];
void dfs(int idx, int l, int r) {
    if (idx == n + 1) {
        if (res < l * r) {
            res = l * r;
            for (int i = 1; i < n + 1; i++) ans[i] = s[i];
        }
        return;
    }
    if ((w[idx] & r) == 0) s[idx] = 'B', dfs(idx + 1, l | w[idx], r);
    if ((w[idx] & l) == 0) s[idx] = 'W', dfs(idx + 1, l, r | w[idx]);
}

int main() {
    cin >> n;
    for (int i = 1; i < n + 1; i++) scanf("%d", w + i);
    res = -INF;
    dfs(1, 0, 0);
    printf("%lld\n", res);
    puts(ans + 1);
    return 0;
}