#include <bits/stdc++.h>

using namespace std;

void solve() {
    int n;
    cin >> n;
    vector<vector<char>> res(n, vector<char>(n, '.'));
    if (n % 3 == 0) {
        for (int i = 0; i < n; i += 2) {
            for (int j = 0; j + 3 < n; j += 3) {
                res[i][j] = res[i][j + 1] = '#';
            }
        }
        for (int i = 0; i + 1 < n; i += 3) {
            res[i][n - 1] = res[i + 1][n - 1] = '#';
            res[i][n - 3] = res[i + 1][n - 3] = '#';
        }
    } else {
        for (int i = 0; i < n; i += 2) {
            for (int j = 0; j + 1 < n; j += 3) {
                res[i][j] = res[i][j + 1] = '#';
            }
        }
        if (n % 3 == 1) {
            for (int i = 0; i + 1 < n; i += 3) {
                res[i].back() = res[i + 1].back() = '#';
            }
        }
    }
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            cout << res[i][j];
        }
        cout << "\n";
    }
}

int main() {
    cin.tie(0)->sync_with_stdio(false);
    int t;
    cin >> t;
    while (t--)solve();
    return 0;
}