#include <bits/stdc++.h>
using namespace std;
#define rep(i, a, n) for(int i = a; i < n; i++)
#define rrep(i, a, n) for(int i = a; i >= n; i--)
#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
// constexpr ll MOD = 1000000007;
constexpr ll MOD = 998244353;
constexpr int IINF = 1001001001;
constexpr ll INF = 1LL<<60;

template<class t,class u> void chmax(t&a,u b){if(a<b)a=b;}
template<class t,class u> void chmin(t&a,u b){if(b<a)a=b;}

int main(){
    int n; cin >> n;
    vector<string> s(n);
    rep(i, 0, n) cin >> s[i];
    int cnt_b = 0, cnt_d = 0, ans = 0;
    rep(i, 0, n){
        cnt_b = 0, cnt_d = 0;
        rep(j, 0, n){
            if(s[i][j] == 'B') cnt_b++;
            if(s[i][j] == '.') cnt_d++;
        }
        if(cnt_b == 0 && cnt_d == 1) ans++;
    }
    rep(i, 0, n){
        cnt_b = 0, cnt_d = 0;
        rep(j, 0, n){
            if(s[j][i] == 'B') cnt_b++;
            if(s[j][i] == '.') cnt_d++;
        }
        if(cnt_b == 0 && cnt_d == 1) ans++;
    }
    cnt_b = 0, cnt_d = 0;
    for(int i = 0, j = 0; i < n && j < n; i++, j++){
        if(s[j][i] == 'B') cnt_b++;
        if(s[j][i] == '.') cnt_d++;
    }
    if(cnt_b == 0 && cnt_d == 1) ans++;
    cnt_b = 0, cnt_d = 0;
    for(int i = 0, j = n-1; i < n && 0 <= j; i++, j--){
        if(s[j][i] == 'B') cnt_b++;
        if(s[j][i] == '.') cnt_d++;
    }
    if(cnt_b == 0 && cnt_d == 1) ans++;
    cout << ans << endl;

    return 0;
}