#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC target("sse4")
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;
}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int MOD = 1000000007;
const char nl = '\n';
const int MX = 500001;
int N;
vector<pair<int, int> > A;
pair<int, int> poss(int d) {
  int vals[6];
  for (int i = 0; i < (6); i++) vals[i] = -MX * 4;
  priority_queue<pair<int, int> > v[6];
  v[3].push({-MX * 4, N + 1});
  v[4].push({-MX * 4, N + 1});
  v[5].push({-MX * 4, N + 1});
  for (int i = 0; i < (N); i++) {
    ckmax(vals[3], A[i].first);
    v[3].push({A[i].first, i});
    ckmax(vals[4], A[i].second);
    v[4].push({A[i].second, i});
    ckmax(vals[5], A[i].first - A[i].second);
    v[5].push({A[i].first - A[i].second, i});
  }
  int p = 0;
  for (int i = 0; i < (MX); i++) {
    if (d == 0) {
    }
    while (p < N && A[p].first == i) {
      ckmax(vals[0], -A[p].first);
      ckmax(vals[1], -A[p].second);
      ckmax(vals[2], A[p].second - A[p].first);
      p++;
    }
    for (int j = 3; j < (6); j++) {
      while (v[j].top().second < p) {
        v[j].pop();
      }
      vals[j] = v[j].top().first;
    }
    if (i + vals[0] > d) continue;
    if (vals[3] - i > d) continue;
    int lo = max(0, max(vals[4] - d, vals[2] + i - d));
    int hi = min(d + i - vals[5], d - vals[1]);
    if (lo <= hi && (i != 0 || hi > 0)) {
      if (i > 0) {
        return {i, lo};
      } else
        return {i, max(lo, 1)};
    }
  }
  return {-1, -1};
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin >> N;
  for (int i = 0; i < (N); i++) {
    string S;
    cin >> S;
    int X = 0;
    for (int j = 0; j < ((int)(S).size()); j++)
      if (S[j] == 'B') X++;
    A.push_back({X, (int)(S).size() - X});
  }
  sort(A.begin(), A.end());
  int lo = 0, hi = MX * 4;
  pair<int, int> def = {-1, -1};
  while (lo < hi) {
    int mid = (lo + hi) / 2;
    if (poss(mid) != def) {
      hi = mid;
    } else {
      lo = mid + 1;
    }
  }
  pair<int, int> res = poss(lo);
  cout << lo << nl;
  for (int i = 0; i < (res.first); i++) cout << 'B';
  for (int i = 0; i < (res.second); i++) cout << 'N';
  cout << nl;
  return 0;
}
