#include <bits/stdc++.h>
using namespace std;
const bool debug = 1;
int xl = 1 << 30, xr = -(1 << 30), yl = 1 << 30, yr = -(1 << 30), zl = 1 << 30,
    zr = -(1 << 30);
bool getpod(pair<int, int> p, int s) {
  int pzl = p.first - p.second - s;
  int pzr = p.first - p.second + s;
  int pxl = p.first - s;
  int pxr = p.first + s;
  int pyl = p.second - s;
  int pyr = p.second + s;
  if (pzl <= zl && pzr >= zr && pyl <= yl && pyr >= yr && pxl <= xl &&
      pxr >= xr)
    return 1;
  return 0;
}
int main() {
  if (!debug) {
    cin.tie(0);
    cout.tie(0);
    ios::sync_with_stdio(0);
  }
  int n;
  cin >> n;
  vector<pair<int, int>> pt(n, {0, 0});
  for (int i = 0; i < n; i++) {
    string s;
    cin >> s;
    for (int j = 0; j < s.size(); j++)
      if (s[j] == 'B')
        pt[i].first++;
      else
        pt[i].second++;
  }
  for (int i = 0; i < n; i++) {
    xl = min(pt[i].first, xl);
    xr = max(pt[i].first, xr);
    yl = min(pt[i].second, yl);
    yr = max(pt[i].second, yr);
    zl = min(pt[i].first - pt[i].second, zl);
    zr = max(pt[i].first - pt[i].second, zr);
  }
  vector<pair<int, int>> p(12);
  vector<int> s(12);
  {
    int l = -1, r = 1 << 23;
    while (l + 1 < r) {
      int c = (l + r) / 2;
      pair<int, int> p = {zr + yl, yl + c};
      if (getpod(p, c))
        r = c;
      else
        l = c;
    }
    s[0] = r;
    p[0] = {zr + yl, yl + s[0]};
  }
  {
    int l = -1, r = 1 << 23;
    while (l + 1 < r) {
      int c = (l + r) / 2;
      pair<int, int> p = {xl + c, xl - zl};
      if (getpod(p, c))
        r = c;
      else
        l = c;
    }
    s[1] = r;
    p[1] = {xl + s[1], xl - zl};
  }
  {
    int l = -1, r = 1 << 23;
    while (l + 1 < r) {
      int c = (l + r) / 2;
      pair<int, int> p = {zl + yr, yr - c};
      if (getpod(p, c))
        r = c;
      else
        l = c;
    }
    s[2] = r;
    p[2] = {zl + yr, yr - s[2]};
  }
  {
    int l = -1, r = 1 << 23;
    while (l + 1 < r) {
      int c = (l + r) / 2;
      pair<int, int> p = {xr - c, xr - zr};
      if (getpod(p, c))
        r = c;
      else
        l = c;
    }
    s[3] = r;
    p[3] = {xr - s[3], xr - zr};
  }
  {
    int l = -1, r = 1 << 23;
    while (l + 1 < r) {
      int c = (l + r) / 2;
      pair<int, int> p = {xr - c, yr - c};
      if (getpod(p, c))
        r = c;
      else
        l = c;
    }
    s[4] = r;
    p[4] = {xr - s[4], yr - s[4]};
  }
  {
    int l = -1, r = 1 << 23;
    while (l + 1 < r) {
      int c = (l + r) / 2;
      pair<int, int> p = {xl + c, yl + c};
      if (getpod(p, c))
        r = c;
      else
        l = c;
    }
    s[5] = r;
    p[5] = {xl + s[5], yl + s[5]};
  }
  {
    int l = -1, r = zl - xl + yr;
    while (l + 1 < r) {
      int c = (l + r) / 2;
      pair<int, int> p = {xl + c, yr - c};
      if (getpod(p, c))
        r = c;
      else
        l = c;
    }
    s[6] = r;
    p[6] = {xl + s[6], yr - s[6]};
  }
  {
    int l = -1, r = xr - yl - zr;
    while (l + 1 < r) {
      int c = (l + r) / 2;
      pair<int, int> p = {xr - c, yl + c};
      if (getpod(p, c))
        r = c;
      else
        l = c;
    }
    s[7] = r;
    p[7] = {xr - s[7], yl + s[7]};
  }
  {
    int l = -1, r = xr - zl - yr;
    while (l + 1 < r) {
      int c = (l + r) / 2;
      pair<int, int> p = {xr - c, xr - zl - 2 * c};
      if (getpod(p, c))
        r = c;
      else
        l = c;
    }
    s[8] = r;
    p[8] = {xr - s[8], xr - zl - 2 * s[8]};
  }
  {
    int l = -1, r = zr + yr - xr;
    while (l + 1 < r) {
      int c = (l + r) / 2;
      pair<int, int> p = {zr + yr - 2 * c, yr - c};
      if (getpod(p, c))
        r = c;
      else
        l = c;
    }
    s[9] = r;
    p[9] = {zr + yr - 2 * s[9], yr - s[9]};
  }
  {
    int l = -1, r = yl + zr - xl;
    while (l + 1 < r) {
      int c = (l + r) / 2;
      pair<int, int> p = {xl + c, xl - zr + 2 * c};
      if (getpod(p, c))
        r = c;
      else
        l = c;
    }
    s[10] = r;
    p[10] = {xl + s[10], xl - zr + 2 * s[10]};
  }
  {
    int l = -1, r = xl - zl - yl;
    while (l + 1 < r) {
      int c = (l + r) / 2;
      pair<int, int> p = {zl + yl + 2 * c, yl + c};
      if (getpod(p, c))
        r = c;
      else
        l = c;
    }
    s[11] = r;
    p[11] = {zl + yl + 2 * s[11], yl + s[11]};
  }
  int iout = 0;
  for (int i = 0; i < 12; i++)
    if (s[i] < s[iout] && getpod(p[i], s[i])) iout = i;
  cout << s[iout] << '\n';
  for (int i = 0; i < p[iout].first; i++) cout << 'B';
  for (int i = 0; i < p[iout].second; i++) cout << 'N';
  return 0;
}
