#include<bits/stdc++.h>
using namespace std;
char a[100005],b[100005];
char ans[7][100005];
int n;
void sol()
{
    cin>>n;
    int ta=0,tb=0;
    for(int i=1;i<=n;i++)
    {
        cin>>a[i];
        if(a[i]=='#')ta++;
    }
    for(int i=1;i<=n;i++)
    {
        cin>>b[i];
        if(b[i]=='#')tb++;
    }
    if((ta==n&&tb==n))
    {
        cout<<"Yes\n";
        for(int j=0;j<7;j++)
        {
            for(int i=1;i<=n;i++)
                cout<<a[i];
            cout<<'\n';
        }
        return;
    }
    if(ta==n||tb==n)
    {
        cout<<"No\n";
        return;
    }
    for(int i=1;i<=n;i++)
    {
        ans[0][i]=a[i],ans[6][i]=b[i];
        if(a[i]=='#')
            ans[1][i]='.';
        else ans[1][i]='#';
        if(b[i]=='#')
            ans[5][i]='.';
        else ans[5][i]='#';
    }
    int l=1,r=1;
    while(ans[1][l]==ans[1][l+1])l++;
    if(ans[1][l]=='#')l++;
    while(ans[5][r]==ans[5][r+1])r++;
    if(ans[5][r]=='#')r++;
    for(int i=2;i<=4;i++)
        for(int j=1;j<=n;j++)
            ans[i][j]='.';
    ans[2][l]='#';
    ans[4][r]='#';
    if(l==r||abs(r-l)==1)
        ans[3][r]='#';
    else
    {
        if(l>r)swap(l,r);
        for(int i=l+1;i<=r-1;i++)
            ans[3][i]='#';
    }
    cout<<"Yes\n";
    for(int i=0;i<7;i++)
    {
        for(int j=1;j<=n;j++)
            cout<<ans[i][j];
        cout<<'\n';
    }
}
int main(){
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    int t=1;
    cin>>t;
    while(t--)
        sol();
    return 0;
}
/*
4
4
#..#
.##.
5
##.#.
.#.##
6
######
.####.
27
.######.######.####.#.#####
.####...####..#.......#####
Yes
#..#
.##.
#...
.#..
.#..
#..#
.##.
Yes
##.#.
..#.#
.#...
.#...
.#...
#.#..
.#.##
No
Yes
.######.######.####.#.#####
#......#......#....#.#.....
.#.........................
.#.........................
.#.........................
#....###....##.#######.....
.####...####..#.......#####
*/