#include <bits/stdc++.h>
const long long INF = 0x3f3f3f3f3f3f3f3fLL;
const int inf = 0x3f3f3f3f;
const int mod = 1e9 + 7;
const double eps = 1e-6;
const int maxn = 5e5 + 20;
template <class T>
inline void read(T& x) {
  int sign = 1;
  char c = getchar();
  x = 0;
  while (c > '9' || c < '0') {
    if (c == '-') sign = -1;
    c = getchar();
  }
  while (c >= '0' && c <= '9') {
    x = x * 10 + c - '0';
    c = getchar();
  }
  x *= sign;
}
using namespace std;
int n;
char c[maxn];
std::pair<int, int> a[maxn];
inline int get(std::pair<int, int>& p1, std::pair<int, int>& p2) {
  int x = p1.first - p2.first, y = p1.second - p2.second;
  if (x < 0 && y < 0) {
    x = -x;
    y = -y;
  }
  if (x >= 0 && y >= 0) return max(x, y);
  if (x < 0) x = -x;
  if (y < 0) y = -y;
  return x + y;
}
inline int g(std::pair<int, int> p1) {
  int ans = 0;
  for (register int i = 1; i <= n; ++i) {
    ans = max(ans, get(p1, a[i]));
  }
  return ans;
}
std::pair<int, int> f(int x) {
  std::pair<int, int> ans = {inf, inf};
  int l = 0, r = maxn - 1;
  if (!x) ++l;
  while (l <= r) {
    int k1 = l + (r - l) / 3, k2 = r - (r - l) / 3;
    int ans1 = g({x, k1}), ans2 = g({x, k2});
    if (ans1 > ans2) {
      l = k1 + 1;
      if (ans2 < ans.first) {
        ans = {ans2, k2};
      }
    } else {
      r = k2 - 1;
      if (ans1 < ans.first) {
        ans = {ans1, k1};
      }
    }
  }
  return ans;
}
int main() {
  read(n);
  for (register int i = 1; i <= n; ++i) {
    scanf("%s", c + 1);
    int len = strlen(c + 1);
    int cnt = 0;
    for (int j = 1; c[j]; j++) {
      cnt += (c[j] == 'N');
    }
    a[i] = {cnt, len - cnt};
  }
  int maxv = inf;
  int L, R;
  int l = 0, r = maxn - 1;
  while (l <= r) {
    int k1 = l + (r - l) / 3, k2 = r - (r - l) / 3;
    std::pair<int, int> ans1 = f(k1), ans2 = f(k2);
    if (ans1.first > ans2.first) {
      l = k1 + 1;
      if (ans2.first < maxv) {
        maxv = ans2.first;
        L = k2;
        R = ans2.second;
      }
    } else {
      r = k2 - 1;
      if (ans1.first < maxv) {
        maxv = ans1.first;
        L = k1;
        R = ans1.second;
      }
    }
  }
  printf("%d\n", maxv);
  for (int i = 1; i <= R; i++) putchar('B');
  for (int i = 1; i <= L; i++) putchar('N');
}
