#include <bits/stdc++.h>
using namespace std;
template <class T>
bool ckmin(T& a, const T& b) {
  return b < a ? a = b, 1 : 0;
}
template <class T>
bool ckmax(T& a, const T& b) {
  return a < b ? a = b, 1 : 0;
}
struct line {
  int type;
  int pos;
  line(int t, int p) {
    type = t;
    pos = p;
  }
};
pair<bool, pair<int, int> > intersect(line l1, line l2) {
  if (l1.type == l2.type) return make_pair(false, make_pair(0, 0));
  if (l1.type > l2.type) swap(l1, l2);
  if (l1.type == 0) {
    if (l2.type == 1) {
      return make_pair(true, make_pair(l1.pos - l2.pos, l1.pos));
    } else {
      return make_pair(true, make_pair(l2.pos, l1.pos));
    }
  } else {
    return make_pair(true, make_pair(l2.pos, l1.pos + l2.pos));
  }
}
const int MAX_N = 300005;
int n;
pair<int, int> arr[MAX_N];
int minx = 1e9;
int maxx = 0;
int miny = 1e9;
int maxy = 0;
int minyx = 1e9;
int maxyx = -1e9;
bool fit(pair<int, int> center, int r, pair<int, int> coords) {
  if (coords.first < center.first - r || coords.second > center.second + r)
    return 0;
  if (coords.first > center.first + r || coords.second < center.second - r)
    return 0;
  int val = center.second - center.first;
  int val2 = coords.second - coords.first;
  if (val2 < val - r || val2 > val + r) return 0;
  return 1;
}
pair<bool, pair<int, int> > poss(int r) {
  vector<line> lines;
  lines.push_back(line(0, miny + r));
  lines.push_back(line(0, maxy - r));
  lines.push_back(line(1, minyx + r));
  lines.push_back(line(1, maxyx - r));
  lines.push_back(line(2, minx + r));
  lines.push_back(line(2, maxx - r));
  for (int i = 0; i < (int)lines.size(); i++) {
    for (int j = i + 1; j < (int)lines.size(); j++) {
      pair<bool, pair<int, int> > p = intersect(lines[i], lines[j]);
      if (!p.first) continue;
      pair<int, int> center = p.second;
      bool good = 1;
      for (int i = 0; i < n; i++) {
        if (!fit(center, r, arr[i])) {
          good = 0;
          break;
        }
      }
      if (good) {
        return make_pair(true, center);
      }
    }
  }
  return make_pair(false, make_pair(0, 0));
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cin >> n;
  for (int i = 0; i < n; i++) {
    string second;
    cin >> second;
    pair<int, int> res = {0, 0};
    for (char c : second) {
      if (c == 'B')
        res.first++;
      else
        res.second++;
    }
    arr[i] = res;
  }
  for (int i = 0; i < n; i++) {
    ckmin(minx, arr[i].first);
    ckmin(miny, arr[i].second);
    ckmin(minyx, arr[i].second - arr[i].first);
    ckmax(maxx, arr[i].first);
    ckmax(maxy, arr[i].second);
    ckmax(maxyx, arr[i].second - arr[i].first);
  }
  int lo = -1;
  int hi = 1e8;
  while (lo + 1 != hi) {
    int mid = (lo + hi) / 2;
    if (poss(mid).first)
      hi = mid;
    else
      lo = mid;
  }
  cout << hi << "\n";
  pair<int, int> center = poss(hi).second;
  for (int i = 0; i < center.first; i++) cout << 'B';
  for (int i = 0; i < center.second; i++) cout << 'N';
  cout << "\n";
}
