#include <bits/stdc++.h>
using namespace std;
inline int qr() {
  int f = 0, fu = 1;
  char c = getchar();
  while (c < '0' || c > '9') {
    if (c == '-') fu = -1;
    c = getchar();
  }
  while (c >= '0' && c <= '9') {
    f = (f << 3) + (f << 1) + c - 48;
    c = getchar();
  }
  return f * fu;
}
const int N = 3e5 + 10;
string s;
int n;
int maxa, mina = 0x3f3f3f3f, maxb, minb = 0x3f3f3f3f, mxd = -0x3f3f3f3f,
          mnd = 0x3f3f3f3f;
inline pair<int, int> check(int x) {
  int minx = max(0, maxa - x), maxx = mina + x, miny = max(0, maxb - x),
      maxy = minb + x, mind = mxd - x, maxd = mnd + x;
  if (minx > maxx || miny > maxy || mind > maxd || miny - maxx > maxd ||
      maxy - minx < mind)
    return {-1, -1};
  if (maxd >= maxy - minx && mind <= miny - maxx) return {maxx, maxy};
  if (maxd <= maxy - maxx) return {maxx, maxx + maxd};
  if (maxd <= maxy - minx) return {maxy - maxd, maxy};
  if (mind >= maxy - maxx) return {maxy - mind, maxy};
  if (mind >= miny - maxx) return {maxx, maxx + mind};
}
int main() {
  n = qr();
  for (register int i = 1; i <= n; ++i) {
    cin >> s;
    int a = count(s.begin(), s.end(), 'N'), b = s.size() - a;
    mina = min(mina, a), maxa = max(maxa, a);
    minb = min(minb, b), maxb = max(maxb, b);
    mnd = min(mnd, b - a), mxd = max(mxd, b - a);
  }
  int l = 0, r = 6e5;
  while (l < r) {
    int mid = (l + r) >> 1;
    if (check(mid).first == -1)
      l = mid + 1;
    else
      r = mid;
  }
  printf("%d\n", l);
  pair<int, int> ans = check(l);
  for (register int i = 1; i <= ans.first; ++i) putchar('N');
  for (register int i = 1; i <= ans.second; ++i) putchar('B');
  return 0;
}
