#include <bits/stdc++.h>
using namespace std;
template <class T = int>
T read() {
  T x = 0;
  char ch = 0;
  bool f = false;
  while (!isdigit(ch)) f |= (ch = getchar()) == '-';
  for (; isdigit(ch); ch = getchar()) x = x * 10 + (ch ^ '0');
  return f ? -x : x;
}
int ax, ay;
bool ok(int xl, int xr, int yl, int yr, int dl, int dr) {
  if (xl > xr || yl > yr || dl > dr) return false;
  int rdl = xl - yr;
  int rdr = xr - yl;
  if (rdr >= dl && dr >= rdl) {
    int d = xr - yr;
    if (d >= dl && d <= dr) {
      ax = xr;
      ay = yr;
    } else if (d <= dr) {
      ax = xr;
      ay = yr - (dl - d);
    } else {
      ax = xr - (d - dr);
      ay = yr;
    }
    return ax || ay;
  }
  return false;
}
void dmax(int &a, int b) { a = max(a, b); }
void dmin(int &a, int b) { a = min(a, b); }
const int N = 500500;
int n;
int x[N], y[N];
bool test(int d) {
  int xl = 0, xr = 1e8, yl = 0, yr = 1e8, dl = -1e8, dr = 1e8;
  for (int i = (int)(1); i <= (int)(n); i++) {
    dmax(xl, x[i] - d);
    dmin(xr, x[i] + d);
    dmax(yl, y[i] - d);
    dmin(yr, y[i] + d);
    dmax(dl, x[i] - y[i] - d);
    dmin(dr, x[i] - y[i] + d);
  }
  return ok(xl, xr, yl, yr, dl, dr);
}
int main() {
  n = read();
  static char s[N];
  for (int i = (int)(1); i <= (int)(n); i++) {
    scanf("%s", s);
    int l = strlen(s);
    for (int j = 0; j < (int)(l); j++) (s[j] == 'N' ? x[i] : y[i])++;
  }
  int l = 0, r = 1e7;
  while (l < r) {
    int mid = (l + r) >> 1;
    if (test(mid))
      r = mid;
    else
      l = mid + 1;
  }
  printf("%d\n", l);
  test(l);
  for (int _ = 0; _ < (int)(ax); _++) putchar('N');
  for (int _ = 0; _ < (int)(ay); _++) putchar('B');
  printf("\n");
  return 0;
}
