#include <bits/stdc++.h>
#pragma GCC optimize("fast-math")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC diagnostic ignored "-Woverflow"
using namespace std;
const short INF16 = ~(1 << 15);
const int INF32 = 2e9 + 11;
const int SZ = 4e5 + 11;
const int SZ2 = int(1e6 + 11);
const int mod = 998244353;
const int mod2 = 998244353;
const int PIVO = 3e5 + 11;
const long long INF64 = 8e18;
const long long P1 = 53;
const long long P2 = 47;
const long double eps = 1e-10;
const long double PI = acosl(-1);
inline long long MOD(long long x) {
  x %= mod, x += mod;
  return x % mod;
}
inline long long MOD(long long x, long long m) {
  x %= m, x += m;
  return x % m;
}
inline long long T(int x) { return 1ll * x * (x + 1) >> 1; }
inline long long TT(int x) { return 1ll * x * (x + 1) * (x + 2) / 6; }
inline long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
inline long long lcm(long long a, long long b) { return a * b / gcd(a, b); }
long long fpow(long long a, long long b, long long mod) {
  if (!b) return 1;
  if (b == 1) return a % mod;
  if (b & 1) return fpow(a, b ^ 1, mod) * a % mod;
  long long d = fpow(a, b >> 1, mod);
  return d * d % mod;
}
long long fpow(long long a, long long b) {
  if (!b) return 1;
  if (b == 1) return a;
  if (b & 1) return fpow(a, b ^ 1) * a;
  long long d = fpow(a, b >> 1);
  return d * d;
}
int xx[PIVO], yy[PIVO];
int n;
int f(int x, int y) {
  int ans = 0;
  for (int i = 0; i < n; i++) {
    int loc = 0;
    int a = xx[i];
    int b = yy[i];
    if ((a >= x) && (b >= y)) {
      int mn = min(a - x, b - y);
      a -= mn;
      b -= mn;
      loc += mn;
    } else if ((a <= x) && (b <= y)) {
      int mn = min(x - a, y - b);
      a += mn;
      b += mn;
      loc += mn;
    }
    loc += abs(a - x) + abs(b - y);
    ans = max(ans, loc);
  }
  return ans;
}
pair<int, int> g(int x) {
  int l = (x == 0 ? 1 : 0), r = 5e5 + 11, m1, m2;
  int y = 0;
  int ans = INF32;
  while (r - l > 3) {
    m1 = l + (r - l) / 3;
    m2 = r - (r - l) / 3;
    if (f(x, m1) < f(x, m2))
      r = m2;
    else
      l = m1;
  }
  for (int i = l; i <= r; i++) {
    int kek = f(x, i);
    if (ans > kek) {
      ans = kek;
      y = i;
    }
  }
  return {ans, y};
}
void Solve(int num_test) {
  cin >> n;
  set<pair<int, int>> st;
  for (int i = 0; i < n; i++) {
    string s;
    cin >> s;
    int x = 0, y = 0;
    for (char c : s) x += (c == 'B'), y += (c == 'N');
    st.insert({x, y});
  }
  n = st.size();
  int inow = 0;
  for (auto p : st) xx[inow] = p.first, yy[inow++] = p.second;
  int l = 0, r = 5e5 + 11, m1, m2;
  int xans = 0, yans = 0;
  int ans = INF32;
  while (r - l > 3) {
    m1 = l + (r - l) / 3;
    m2 = r - (r - l) / 3;
    if (g(m1) < g(m2))
      r = m2;
    else
      l = m1;
  }
  for (int i = l; i <= r; i++) {
    auto p = g(i);
    if (p.first < ans) {
      ans = p.first;
      xans = i;
      yans = p.second;
    }
  }
  cout << f(xans, yans) << '\n';
  while (xans--) cout << 'B';
  while (yans--) cout << 'N';
  cout << '\n';
}
signed main() {
  ios_base::sync_with_stdio(NULL);
  cin.tie(NULL);
  cout.tie(NULL);
  cout << fixed << setprecision(10);
  srand(time(NULL));
  int test = 1;
  for (int i = 1; i <= test; i++) Solve(i);
}
