#include <bits/stdc++.h>
using namespace std;
const int MAXN = 105;
char str[MAXN][MAXN];
void draw(int dx, int dy, int n) {
	if (n < 2) return;
	if (n == 2) return str[dx][dy] = str[dx][dy + 1] = '#', void();
	if (n == 3) return str[dx][dy] = str[dx][dy + 1] = str[dx + 2][dy] = str[dx + 2][dy + 1] = '#', void();
	if (n % 2 == 0) {
		for (int i = 1; i < n / 2; i++) {
			str[dx][dy + 2 * i - 2] = str[dx + 1][dy + 2 * i - 2] = '#';
			str[dx + 2 * i + 1][dy] = str[dx + 2 * i + 1][dy + 1] = '#';
			str[dx + n - 1][dy + 2 * i + 1] = str[dx + n - 2][dy + 2 * i + 1] = '#';
			str[dx + 2 * i - 2][dy + n - 1] = str[dx + 2 * i - 2][dy + n - 2] = '#';
		}
		draw(dx + 3, dy + 3, n - 6);
	}
	else if (n % 3 == 1) {
		for (int i = 1; i <= n / 3; i++) {
			str[dx][dy + 3 * i - 3] = str[dx][dy + 3 * i - 2] = '#';
			str[dx + 3 * i - 1][dy] = str[dx + 3 * i][dy] = '#';
			str[dx + 3 * i - 3][dy + n - 1] = str[dx + 3 * i - 2][dy + n - 1] = '#';
			str[dx + n - 1][dy + 3 * i - 1] = str[dx + n - 1][dy + 3 * i] = '#';
		}
		draw(dx + 2, dy + 2, n - 4);
	}
	else if (n % 3 == 2) {
		for (int i = 1; i <= n / 2 + 1; i++) for (int j = 1; j <= n / 3 + 1; j++) {
			str[dx + i * 2 - 2][dy + j * 3 - 3] = str[dx + i * 2 - 2][dy + j * 3 - 2] = '#';
		}
	}
	else {
		for (int i = 1; i <= n; i++) for (int j = 1; j <= n; j++) str[dx + i - 1][dy + j - 1] = '?';
	}
}
int main() {
	int t; scanf("%d", &t); while (t--) {
		int n; scanf("%d", &n);
		for (int i = 1; i <= n; i++) for (int j = 1; j <= n; j++) str[i][j] = '.';
		for (int i = 1; i <= n; i++) str[i][n + 1] = 0;
		draw(1, 1, n);
		for (int i = 1; i <= n; i++) puts(str[i] + 1);
	}
}