#define _USE_MATH_DEFINES

#include <iostream>		//cin, cout
#include <vector>		//vector
#include <algorithm>	//sort,min,max,count
#include <string>		//string,getline, to_string
#include <cstdlib>		//abs(int)
#include <utility>		//swap, pair
#include <deque>		//deque
#include <climits>		//INT_MAX
#include <bitset>		//bitset
#include <cmath>		//sqrt, ceil. M_PI, pow, sin
#include <ios>			//fixed
#include <iomanip>		//setprecision
#include <sstream>		//stringstream
#include <numeric>		//gcd, assumlate
#include <random>		//randam_device
#include <limits>		//numeric_limits
#include <time.h>       //tm

using namespace std;
constexpr int64_t D_MOD = 1000000007;
constexpr int64_t F_MOD = 998244353;


int main() {

    int N;
    cin >> N;

    vector<string> S(N);

    int ans = 0;
    int cntd = 0;
    int cntb = 0;

    for (int i = 0; i < N; i++) {
        cin >> S.at(i);

        cntd = 0;
        cntb = 0;
        for (int j = 0; j < N; j++) {
            if (S.at(i).at(j) == '.') {
                cntd++;
            }
            else if (S.at(i).at(j) == 'B') {
                cntb++;
            }
        }
        if (cntd == 1 && cntb == 0) {
            ans++;
        }
    }

    for (int i = 0; i < N; i++) {

        cntd = 0;
        cntb = 0;
        for (int j = 0; j < N; j++) {
            if (S.at(j).at(i) == '.') {
                cntd++;
            }
            else if (S.at(j).at(i) == 'B') {
                cntb++;
            }
        }
        if (cntd == 1 && cntb == 0) {
            ans++;
        }
    }

    cntd = 0;
    cntb = 0;
    for (int i = 0; i < N; i++) {
        if (S.at(i).at(i) == '.') {
            cntd++;
        }
        else if (S.at(i).at(i) == 'B') {
            cntb++;
        }
    }
    if (cntd == 1 && cntb == 0) {
        ans++;
    }

    cntd = 0;
    cntb = 0;
    for (int i = 0; i < N; i++) {
        if (S.at(i).at(N - i - 1) == '.') {
            cntd++;
        }
        else if (S.at(i).at(N - i - 1) == 'B') {
            cntb++;
        }
    }
    if (cntd == 1 && cntb == 0) {
        ans++;
    }

    cout << ans << endl;

    return 0;

}