#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;

using i32 = int;
using i64 = long long;
using u64 = unsigned long long;
using i128 = __int128_t;
using f64 = long double;
using p2 = pair<i64, i64>;
using el = tuple<i64, i64, i64>;
using mint = atcoder::modint998244353;

void _main();
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  _main();
}

i128 pow(i128 x, i128 n) {
  i64 res = 1;
  i64 t = x;
  while (n > 0) {
    if (n & 1) {
      res = res * t;
    }
    t = t * t;
    n >>= 1;
  }
  return res;
}
i64 pow(i64 x, i64 n, i64 m) {
  i64 res = 1;
  i64 t = x % m;
  while (n > 0) {
    if (n & 1) {
      res = res * t % m;
    }
    t = t * t % m;
    n >>= 1;
  }
  return res;
}

void _main() {
  i64 n;
  cin >> n;
  vector<i64> a(n);
  for (i64 i = 0; i < n; i++) {
    cin >> a[i];
  }
  i64 mx = -1;
  string ans;
  for (i64 x = 0; x < 1 << 12; x++) {
    i64 y = (1 << 12) - 1 - x;
    bool ok = true;
    i64 w = 0, b = 0;
    string cur(n, '.');
    for (i64 i = 0; i < n; i++) {
      if ((x | a[i]) == x) {
        w |= a[i];
        cur[i] = 'W';
      } else if ((y | a[i]) == y) {
        b |= a[i];
        cur[i] = 'B';
      } else {
        ok = false;
      }
    }
    if (!ok) continue;
    assert((w & b) == 0);
    if (mx < w * b) {
      mx = w * b;
      swap(ans, cur);
    }
  }
  cout << mx << "\n";
  cout << ans << "\n";
}