#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
  #define _GLIBCXX_DEBUG
#else
  #define Debug(...) void(0)
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

int main() {
  int n;
  cin >> n;
  vector Grid(n, vector<char>(n));
  rep(i, n) rep(j, n) cin >> Grid[i][j];
  int ans = 0;
  const int INF = 1e9;
  // yoko
  rep(i, n) {
    int cnt = 0;
    rep(j, n) {
      if (Grid[i][j] == 'B') cnt = INF;
      if (Grid[i][j] == '.') cnt++;
    }
    if (cnt <= 1) ans++;
  }
  // tate
  rep(j, n) {
    int cnt = 0;
    rep(i, n) {
      if (Grid[i][j] == 'B') cnt = INF;
      if (Grid[i][j] == '.') cnt++;
    }
    if (cnt <= 1) ans++;
  }
  // naname 1
  int cnt1 = 0;
  rep(i, n) {
    if (Grid[i][i] == 'B') cnt1 = INF;
    if (Grid[i][i] == '.') cnt1++;
  }
  if (cnt1 <= 1) ans++;
  // naname 2
  int cnt2 = 0;
  rep(i, n) {
    if (Grid[i][n - 1 - i] == 'B') cnt2 = INF;
    if (Grid[i][n - 1 - i] == '.') cnt2++;
  }
  if (cnt2 <= 1) ans++;
  cout << ans << endl;
  return 0;
}