import std.conv, std.functional, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.container, std.math, std.numeric, std.range, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }


int N;
string[] S;
bool[][] A;

int solve() {
  int ret;
  foreach (s; 0 .. 3) foreach (t; 0 .. 3) {
    auto a = new bool[][](N, N);
    foreach (x; 0 .. N) foreach (y; 0 .. N) {
      a[x][y] = A[x][y];
    }
    bool check(int x0, int x1, int y0, int y1) {
      foreach (x; x0 .. x1) foreach (y; y0 .. y1) {
        if (!a[x][y]) {
          return false;
        }
      }
      return true;
    }
    
    int score;
    if (s == 1) {
      if (check(0, 1, 0, N - 1)) {
        ++score;
        a[0][0 .. N - 1] = false;
      }
    }
    if (s == 2) {
      if (check(0, 1, 1, N)) {
        ++score;
        a[0][1 .. N] = false;
      }
    }
    if (t == 1) {
      if (check(N - 1, N, 0, N - 1)) {
        ++score;
        a[N - 1][0 .. N - 1] = false;
      }
    }
    if (t == 2) {
      if (check(N - 1, N, 1, N)) {
        ++score;
        a[N - 1][1 .. N] = false;
      }
    }
    foreach (y; 0 .. N) {
      if (check(0, N - 1, y, y + 1) || check(1, N, y, y + 1)) {
        ++score;
      }
    }
    chmax(ret, score);
  }
  return ret;
}

void main() {
  try {
    for (; ; ) {
      N = readInt();
      S = new string[N];
      foreach (x; 0 .. N) {
        S[x] = readToken();
      }
      A = new bool[][](N, N);
      foreach (x; 0 .. N) foreach (y; 0 .. N) {
        A[x][y] = (S[x][y] == '.');
      }
      int ans;
      foreach (dir; 0 .. 2) {
        chmax(ans, solve());
        foreach (x; 0 .. N) foreach (y; x + 1 .. N) {
          swap(A[x][y], A[y][x]);
        }
      }
      writeln(ans);
    }
  } catch (EOFException e) {
  }
}