#include<bits/stdc++.h>
#define x first
#define y second
#define endl '\n'
#define debug(x) cout<<#x<<" = "<<x<<endl
#define pb push_back
#define maxheap(x) priority_queue<x,vector<x>,less<x> > 
#define minheap(x) priority_queue<x,vector<x>,greater<x> > 
#pragma GCC optimize(2)
using namespace std;
typedef long long ll;
const int N = 2e6 + 10;
const int INF = 2147483647;
ll e[N];
typedef pair<int,int> pii;
ll qpow(ll a,ll b,ll p)
{
    ll res = 1;
    while(b > 0)
	{
        if(b & 1) res = res * a % p;
        a = a * a % p;b >>= 1;
    }
    return res;
}
ll exgcd(ll a,ll b,ll &x,ll &y)
{
    if(b == 0)
	{
        x = 1,y = 0;
        return a;
    }
    ll d = exgcd(b,a % b,y,x);
    y -= a / b * x;
    return d;
}
void solve()
{
	int n;
	cin >> n;
	string a,b;
	cin >> a >> b;
	int cnt = 0;
	for(int i = 0;i < n;i ++)
	{
		if(a[i] == '.')
		{
			cnt ++;
			break;
		}
	}
	for(int i = 0;i < n;i ++)
	{
		if(b[i] == '.')
		{
			cnt ++;
			break;
		}
	}
	if(cnt == 0)
	{
		cout << "Yes" << endl;
		for(int i = 1;i <= 7;i ++)
		{
			for(int j = 0;j < n;i ++)
			cout << '#';
			cout << endl;
		}
		return ;
	}
	if(cnt == 1)
	{
		cout << "No" << endl;
		return ;
	} 
	string aa = "";
	string bb = "";
	for(int i = 0;i < n;i ++)
	{
		if(a[i] == '.') aa += '#';
		else aa +='.';
	}
	for(int i = 0;i < n;i ++)
	{
		if(b[i] == '.') bb += '#';
		else bb +='.';
	}
	cout << "Yes" << endl;
	cout << a << endl;
	cout << aa << endl;
	cout << aa << endl;
	string ans = "";
	for(int i = 0;i < n;i ++)
	{
		if(aa[i] == '.' && bb[i] == '.') ans += '#';
		else if(aa[i] == '.' && bb[i] == '#') ans += '#';
		else ans += '.';
	}
	cout << ans << endl;
	cout << bb << endl;
	cout << bb << endl;
	cout << b << endl;
}
int main()
{
	ios :: sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int t;
	cin >> t;
	while(t --)
	{
		solve();
	}
	return 0;
}