#include "testlib.h"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll MAX_N = 1'000;

int main(int argc, char* argv[]) {
    registerValidation(argc, argv);
    ll N = inf.readLong(1, MAX_N, "N");
    inf.readEoln();
    vector<string> S(N);
    int ans = -N*N*(N-1)/2;
    int res = 0;
    int cntw = 0, cntb = 0;
    for(int i = 0; i < N; i++)
    {
        S[i] = inf.readString(format("[.#]{%d,%d}",2*N, 2*N), "S_"+to_string(i));
        int cnt = 0;
        for(int j = 0; j < 2*N; j++)
        {
            if(S[i][j] == '.')
            {
                cntw++;
                ans += j;
                cnt++;
            }
            else
            {
                cntb++;
            }
        }
        ans += abs(res);
        res += cnt - N;
    }
    inf.ensuref(cntw == N*N && cntb == N*N, "invalid S w&b");
    inf.readEof();
    cout << ans << endl;
}