#include<bits/stdc++.h>
#define int long long
#define ll long long
#define endl '\n'
using namespace std;
const int N=1e5+5;
int n;
string a,b;
char c[10][N];
void pri()
{
	cout<<"Yes"<<endl;
	for(int i=1;i<=7;i++)
	{
		for(int j=1;j<=n;j++)
			cout<<c[i][j];
		cout<<endl;
	}
	return;
}
void solve(){
	cin>>n>>a>>b;
	int c1=0,c2=0;
	for(int i=1;i<=7;i++)
		for(int j=1;j<=n;j++)
			c[i][j]='.';
	for(int i=1;i<=n;i++)
		c1+=(a[i-1]=='#'),c2+=(b[i-1]=='#');
	if(c1==n||c2==n){
		if(c1==n&&c2==n){
			cout<<"Yes"<<endl;
			for(int i=1;i<=7;i++){
				for(int j=1;j<=n;j++)
					cout<<'#';
				cout<<endl;
			}
		}else cout<<"No"<<endl;
		return;
	}
	for(int i=1;i<=n;i++)c[1][i]=a[i-1];
	for(int i=1;i<=n;i++)c[7][i]=b[i-1];
	for(int i=1;i<=n;i++){
		c[2][i]=(c[1][i]=='#'?'.':'#');
		c[6][i]=(c[7][i]=='#'?'.':'#');
		c[3][i]=c[1][i];
		c[5][i]=c[7][i];
	}
	for(int i=1;i<=n;i++)
	{
		if(c[3][i]==c[5][i]&&c[3][i]=='.')
		{
			c[4][i]='#';
			pri();
			return;
		}
	}
	for(int i=1;i<=n;i++)
	{
		if(c[3][i]==c[5][i]&&c[3][i]=='#')
		{
			c[4][i]='#';
			if((i+1<=n&&c[3][i+1]=='#')||(i-1>=1&&c[3][i-1]=='#'))
				c[3][i]='.';
			if((i+1<=n&&c[5][i+1]=='#')||(i-1>=1&&c[5][i-1]=='#'))
				c[5][i]='.';
			pri();
		}
	}
	for(int i=1;i<=n;i++)
	{
		c[4][i]=c[3][i];
	}
	pri();
}
int T=1;
signed main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	cin>>T;
	for(int kase=1;kase<=T;kase++){
		solve();
	}
	return 0;
}
/*
4
4
#..#
.##.
5
##.#.
.#.##
6
######
.####.
27
.######.######.####.#.#####
.####...####..#.......#####
*/