#include <bits/stdc++.h>
using namespace std;
const int N = 3e5 + 5, M = 5e5 + 5, INF = 0x3fffffff;
template <typename T>
void read(T &x) {
  bool neg = false;
  unsigned char c = getchar();
  for (; (c ^ 48) > 9; c = getchar())
    if (c == '-') neg = true;
  for (x = 0; (c ^ 48) < 10; c = getchar()) x = (x << 3) + (x << 1) + (c ^ 48);
  if (neg) x = -x;
}
int n, x[N], y[N], lx, rx, ly, ry, lxy, rxy;
char s[M];
bool check(int v) {
  lx = x[0] - v, rx = x[0] + v, ly = y[0] - v, ry = y[0] + v,
  lxy = x[0] - y[0] - v, rxy = x[0] - y[0] + v;
  for (int i = 1, i_end = n; i < i_end; ++i) {
    int nlx = x[i] - v, nrx = x[i] + v, nly = y[i] - v, nry = y[i] + v,
        nlxy = x[i] - y[i] - v, nrxy = x[i] - y[i] + v;
    if (nlx > lx) lx = nlx;
    if (nly > ly) ly = nly;
    if (nlxy > lxy) lxy = nlxy;
    if (nrx < rx) rx = nrx;
    if (nry < ry) ry = nry;
    if (nrxy < rxy) rxy = nrxy;
  }
  if (lx > rx) return false;
  if (ly > ry) return false;
  if (lx - ry > lxy) lxy = lx - ry;
  if (rx - ly < rxy) rxy = rx - ly;
  if (lxy > rxy) return false;
  return true;
}
int solve() {
  int l = -1, r = 1.5e6, mid;
  while (r - l > 1) {
    mid = (l + r) >> 1;
    if (check(mid))
      r = mid;
    else
      l = mid;
  }
  return r;
}
int main() {
  int ans = 0;
  read(n);
  for (int i = 0, i_end = n; i < i_end; ++i) {
    scanf("%s", s);
    for (int j = 0; s[j]; ++j)
      if (s[j] == 'B')
        ++x[i];
      else
        ++y[i];
  }
  printf("%d\n", ans = solve());
  check(ans);
  if (ry + lxy < rx)
    rx = ry + lxy;
  else if (ry + rxy > rx)
    ry = rx - rxy;
  while (rx--) putchar('B');
  while (ry--) putchar('N');
  putchar('\n');
  return 0;
}
