#include <bits/stdc++.h>
#define ll long long
#define pii pair<int,int>
using namespace std;


void solve(){
	int n;
	cin>>n;
	string s,t;
	cin>>s>>t;
	int flag1=1,flag2=1;
	for(auto u:s){
		if(u=='.'){
			flag1=0;
			break;
		}
	}
	for(auto u:t){
		if(u=='.'){
			flag2=0;
			break;
		}
	}
	if(flag1^flag2){
		cout<<"No\n";
		return;
	}
	if(flag1&flag2){
		cout<<"Yes\n";
		for(int i=1;i<=7;i++){
			for(int j=1;j<=n;j++)cout<<"#";
			cout<<"\n";
		}
		return;
	}
	cout<<"Yes\n";
	cout<<s<<"\n";
	string r;
	int cnt=0;
	for(auto u:s){
		if(u=='.')r+='#';
		else r+='.',cnt++;
	}
	if(cnt==n-1&&s[0]=='.')r=s;
	else{
		if(r[0]=='#'){
			r[0]='.';
		}
	}
	cout<<r<<"\n";
	if(r[1]=='#'){
		cout<<r<<"\n";
	}
	else{
		string t;
		for(auto u:r){
			if(u=='.')t+="#";
			else t+='.';
		}
		t[0]='.';
		cout<<t<<"\n";
		r=t;
	}
	cout<<"#";
	for(int i=2;i<=n;i++)cout<<".";cout<<"\n";
	vector<string>p;
	s=t;
	p.push_back(t);
	r="";
	cnt=0;
	for(auto u:s){
		if(u=='.')r+='#';
		else r+='.',cnt++;
	}
	if(cnt==n-1&&s[0]=='.')r=s;
	else{
		if(r[0]=='#'){
			r[0]='.';
		}
	}
	p.push_back(r);
	if(r[1]=='#'){
		p.push_back(r);
	}
	else{
		string t;
		for(auto u:r){
			if(u=='.')t+="#";
			else t+='.';
		}
		t[0]='.';
		p.push_back(t);
		r=t;
	}
	reverse(p.begin(),p.end());
	for(auto u:p)cout<<u<<"\n";
}
int main(){
	ios::sync_with_stdio(0),cin.tie(0);
	int t=1;
	cin>>t;
	while(t--)solve();
	return 0;
}
/*
4
4
#..#
.##.
5
##.#.
.#.##
6
######
.####.
27
.######.######.####.#.#####
.####...####..#.......#####

.#################

.??????????????????

2 : ..
-> 3 : .#
*/