#include <bits/stdc++.h>
using namespace std;

int main() {
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);
    int N;
    cin >> N;
    assert(1 <= N && N <= 1'000);
    vector<string> S(N);
    for (int i = 0; i < N; i++) {
        cin >> S[i];
        assert(S[i].size() == 2 * N);
        for (auto c : S[i]) {
            assert(c == '.' || c == '#');
        }
    }
    vector<int> X, Y;
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < 2 * N; j++) {
            if (S[i][j] == '.') {
                X.emplace_back(i);
                Y.emplace_back(j);
            }
        }
    }
    assert(X.size() == N * N && Y.size() == N * N);

    assert(N <= 3);
    long long ans = 0;
    for (auto y : Y) ans += y;
    ans -= N * (N - 1) / 2 * N;
    sort(X.begin(), X.end());
    for (int i = 0; i < N * N; i++) ans += abs(X[i] - i/N);
    cout << ans << endl;
    return 0;
}