/*
    Author : zzugzx
    Lang : C++
    Blog : blog.csdn.net/qq_43756519
*/

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

#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(), (x).end()
#define endl '\n'
#define SZ(x) (int)x.size()
#define mem(a, b) memset(a, b, sizeof(a))

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int mod = 1e9 + 7;
//const int mod = 998244353;

const double eps = 1e-8;
const double pi = acos(-1.0);
const int maxn = 1e6 + 10;
const int N = 1e2 + 10;
const ll inf = 0x3f3f3f3f;
const ll oo = 8e18;
const int dir[][2]={{0, 1}, {1, 0}, {0, -1}, {-1, 0}, {1, 1}, {1, -1}, {-1, 1}, {-1, -1}};
ll Pow(ll a, ll b){
	ll ans = 1;
	while(b > 0){
		if(b & 1){
			ans = ans * a % mod;
		}
		a = a * a % mod;
		b >>= 1;
	}
	return ans;
}
ll inv(ll b){
    return Pow(b, mod - 2) % mod;
}
char g[910][910];
int num[12], n;
void solve() {
    mem(num, 0);
    for (int i = 2; i <= 3 * n; i += 3)
        for (int j = 0; j < 3; j++) {
            int k = i + j, k1 = i + j - 1;
            for (int x = 0; x < k; x++) {
                int y = k - x;
                if (g[x][y] == 'X') num[j]++;
            }
            for (int x = 0; x < k1; x++) {
                int y = k1 - x;
                if (g[x][y] == 'O') num[j]++;
            }
        }
    for (int i = 2; i <= 3 * n; i += 3)
        for (int j = 0; j < 3; j++) {
            int k = i + j, k1 = i + j - 1;
            for (int x = 0; x < k; x++) {
                int y = k - x;
                if (g[x][y] == 'O') num[j + 3]++;
            }
            for (int x = 0; x < k1; x++) {
                int y = k1 - x;
                if (g[x][y] == 'X') num[j + 3]++;
            }
        }
    int t = 0;
    for (int i = 0; i < 6; i++)
        if (num[i] < num[t]) t = i;
    if (t < 3) {
        for (int i = 2; i <= 3 * n; i += 3) {
                int k = i + t, k1 = i + t - 1;
                for (int x = 0; x < k; x++) {
                    int y = k - x;
                    if (g[x][y] == 'X')
                        g[x][y] = 'O';
                }
                for (int x = 0; x < k1; x++) {
                    int y = k1 - x;
                    if (g[x][y] == 'O')
                        g[x][y] = 'X';
                }
        }
    }
    else {
        t -= 3;
        for (int i = 2; i <= 3 * n; i += 3) {
                int k = i + t, k1 = i + t - 1;
                for (int x = 0; x < k; x++) {
                    int y = k - x;
                    if (g[x][y] == 'O')
                        g[x][y] = 'X';
                }
                for (int x = 0; x < k1; x++) {
                    int y = k1 - x;
                    if (g[x][y] == 'X')
                        g[x][y] = 'O';
                }
        }
    }
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
//  freopen("in.txt", "r", stdin);
//  freopen("out.txt", "w", stdout);
    int _;
    cin >> _;
    while (_--) {
        cin >> n;
        for (int i = 1; i <= n; i++)
            for (int j = 1; j <= n; j++) {
                cin >> g[i][j];
            }
        solve();
        for (int i = 1; i <= n; i++, cout << endl)
            for (int j = 1; j <= n; j++)
                cout << g[i][j], g[i][j] = 0;
    }
    return 0;
}
