#include <bits/stdc++.h>

using namespace std;

using pii = pair<int, int>;
using ll = long long;
const int N = 2000010, MOD = 998244353, INF = 0x3f3f3f3f;
int n, m, w[N];


char s[1001][2002];
void solve() {
	scanf("%d", &n);
	for (int i = 1; i < n + 1; i++) scanf("%s", s[i] + 1);
	set<pii> a, b;
	for (int i = 1; i < n + 1; i++) {
		for (int j = 1; j < n * 2 + 1; j++) {
			if (j <= n && s[i][j] == '#') a.insert({i, j});
			if (j > n && s[i][j] == '.') b.insert({i, j});
		}
	}
	int res = 0;
	while (a.size() && b.size()) {
		auto x = *a.begin(), y = *b.begin();
		a.erase(a.begin()), b.erase(b.begin());
		res += abs(x.first - y.first) + abs(x.second - y.second);
	}
	printf("%d\n", res);
}

int main() {
	int T = 1;
	// scanf("%d", &T);
	while (T--) solve();
	return 0;
}