#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1e6 + 5;
int X, Y;
int n;
pair<int, int> arr[MAXN];
bool testx(int x, int y1, int d1, int y2, int d2) {
  X = x;
  Y = max(y1, x - d2);
  return max(y1, x - d2) <= min(y2, x - d1);
}
bool testy(int y, int x1, int d1, int x2, int d2) {
  Y = y;
  X = max(x1, y + d1);
  return max(x1, y + d1) <= min(x2, y + d2);
}
bool check(int k) {
  int mnx = 1e9;
  int mxx = 0;
  int mny = 1e9;
  int mxy = 0;
  int mnd = 1e9;
  int mxd = -1e9;
  for (int i = 1; i <= n; i++) {
    mnx = min(mnx, arr[i].first + k);
    mxx = max(mxx, arr[i].first - k);
    mny = min(mny, arr[i].second + k);
    mxy = max(mxy, arr[i].second - k);
    mnd = min(mnd, arr[i].first - arr[i].second + k);
    mxd = max(mxd, arr[i].first - arr[i].second - k);
  }
  if (mnx < mxx || mny < mxy || mnd < mxd) {
    return false;
  }
  if (testx(mnx, mxy, mxd, mny, mnd)) {
    return true;
  } else if (testx(mxx, mxy, mxd, mny, mnd)) {
    return true;
  } else if (testy(mny, mxx, mxd, mnx, mnd)) {
    return true;
  } else if (testy(mxy, mxx, mxd, mnx, mnd)) {
    return true;
  }
  return false;
}
int main() {
  cin >> n;
  for (int i = 1; i <= n; i++) {
    string s;
    cin >> s;
    for (auto x : s) {
      if (x == 'N') {
        arr[i].first++;
      } else {
        arr[i].second++;
      }
    }
  }
  int l = 0;
  int r = 3e5 + 5;
  int ans = 0;
  check(1);
  while (l <= r) {
    int mid = (l + r) / 2;
    if (check(mid)) {
      ans = mid;
      r = mid - 1;
    } else {
      l = mid + 1;
    }
  }
  check(ans);
  cout << ans << endl;
  for (int i = 1; i <= X; i++) {
    cout << 'N';
  }
  for (int i = 1; i <= Y; i++) {
    cout << 'B';
  }
}
