#include <bits/stdc++.h>
#define int long long
using namespace std;
const int N = 2e5 + 10, INF = 1e18, MOD = 1e9 + 7;
typedef pair<int, int> PII;
typedef unsigned long long ull;
int dx[] = {0, 0, 1, -1}, dy[] = {1, -1, 0, 0};
int arr[N], brr[N];
map<int,int> mp;
map<PII,int> mpp;
vector<PII> vi, g[N];
vector<int> ans;
bool st[N];
int n, m, k;

void solve()
{
	cin >> n;
	string a;
	string b;
	cin >> a >> b;
	string a1 = " " + a + " ";
	string b1 = " " + b + " ";
	if((int)a.find('.') != -1 && (int)b.find('.') != -1){
		string t1 = "", t2 = "", t3 = "" , t4 = "", t5 = "";
		for(int i = 1; i < (int)a1.size() - 1; i ++){
			if(a1[i] == '.' ) t1 += '#';
			else{
				t1 += '.';
			}
			if(b1[i] == '.' ) t4 += '#';
			else{
				t4 += '.';
			}
		}
		int cnt = 0;
		int l = 0,r  = 0;
		for(int i = 0; i < n - 1; i ++){
			if(t1[i] =='#' && t1[i + 1] != '#' && !cnt){
				t2 += ".#";
				cnt ++;
				l = i;
			}else{
				t2 += '.';
			}
		}
		cnt = 0;
		for(int i = 0; i < n - 1; i ++){
			if(t4[i] == '#' && t4[i + 1] != '#' && !cnt){
				t5 += ".#";
				cnt ++;
				r = i;
			}else{
				t5 += ".";
			}
		}
		for(int i = 0; i < n; i ++){
			if(i == l + 1 || i == r + 1)  t3 += ".";
			else t3 += '#';
		}
		cout << "YES\n";
		cout << a << "\n" << t1 << "\n" << t2 << "\n" << t3 << "\n" << t5 << "\n" << t4 << '\n' << b << "\n";
		return;
	}else if((int)a.find('.') == -1 && (int)b.find('.') == -1){
		cout << "YES\n";
		for(int i = 0; i < 7; i ++) cout << a << "\n";
		return;
	}
	cout << "NO\n";
}

signed main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	int T = 1;
	cin >> T;
	while (T --)	solve();
	return 0;
}