#include <bits/stdc++.h>
using namespace std;
const long long INF = 1e18;
const long long MOD = 998244353;
vector<string> vec_splitter(string s) {
  s += ',';
  vector<string> res;
  while (!s.empty()) {
    res.push_back(s.substr(0, s.find(',')));
    s = s.substr(s.find(',') + 1);
  }
  return res;
}
void debug_out(vector<string> __attribute__((unused)) args,
               __attribute__((unused)) int idx,
               __attribute__((unused)) int LINE_NUM) {
  cerr << endl;
}
template <typename Head, typename... Tail>
void debug_out(vector<string> args, int idx, int LINE_NUM, Head H, Tail... T) {
  if (idx > 0)
    cerr << ", ";
  else
    cerr << "Line(" << LINE_NUM << ") ";
  stringstream ss;
  ss << H;
  cerr << args[idx] << " = " << ss.str();
  debug_out(args, idx + 1, LINE_NUM, T...);
}
bool order(int a, int b, int c) { return a >= b and b >= c; }
int32_t main() {
  ios::sync_with_stdio(!cin.tie(NULL));
  int n;
  cin >> n;
  string s;
  long long xmin = INF, xmax = -INF, ymin = INF, ymax = -INF, xymin = INF,
            xymax = -INF;
  long long a, b;
  for (int i = 0; i < n; i++) {
    a = b = 0;
    cin >> s;
    for (auto ch : s) a += (ch == 'B'), b += (ch == 'N');
    xmin = min(xmin, a), xmax = max(xmax, a);
    ymin = min(ymin, b), ymax = max(ymax, b);
    xymin = min(xymin, b - a), xymax = max(xymax, b - a);
  }
  long long hi = 1e6, lo = 0;
  bool flag = false;
  while (hi > lo) {
    long long mid = (hi + lo) / 2;
    xmin += mid, xmax -= mid;
    ymin += mid, ymax -= mid;
    xymin += mid, xymax -= mid;
    bool state = false;
    if (xmin >= xmax and ymin >= ymax and xymin >= xymax) {
      vector<pair<long long, long long>> cand;
      for (int x : {xmin, xmax}) {
        for (int y : {ymin, ymax}) {
          cand.push_back({x, y});
        }
      }
      for (int x : {xmin, xmax}) {
        for (int y : {xymin, xymax}) cand.push_back({x, y + x});
      }
      for (int x : {ymin, ymax})
        for (int y : {xymin, xymax}) cand.push_back({x - y, x});
      for (auto pt : cand) {
        if (pt.first < 0 or pt.second < 0) continue;
        if (pt.first == 0 and pt.second == 0) continue;
        if (order(xmin, pt.first, xmax) and order(ymin, pt.second, ymax) and
            order(xymin, pt.second - pt.first, xymax))
          state = true, a = pt.first, b = pt.second;
      }
    }
    mid *= -1;
    xmin += mid, xmax -= mid;
    ymin += mid, ymax -= mid;
    xymin += mid, xymax -= mid;
    flag |= state;
    mid *= -1;
    42;
    if (!state)
      lo = mid + 1;
    else
      hi = mid;
  }
  cout << lo << "\n";
  for (int i = 0; i < a; i++) cout << "B";
  for (int i = 0; i < b; i++) cout << "N";
}
