#include<bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'

void solve()
{
    int n;
    string a, b;
    // scanf("%lld%s%s",&n,a,b);
    cin >> n ;
    //getchar();
    cin>> a >> b;
    string f(n, '.');
    string ff(n,'#');
    vector<string> s(8,f);
    s[1] = a;
    s[7] = b;
    if(a==ff&&b==ff)
    {
        cout<<"Yes"<<endl;
        for(int i=0;i<7;i++)
        {
            cout<<a<<endl;
        }
        return;
    }
    if(a==ff&&b!=ff)
    {
        cout<<"No"<<endl;
        return;
    }
    if(a!=ff&&b==ff)
    {
        cout<<"No"<<endl;
        return;
    }
    cout<<"Yes"<<endl;
    for(int i=0;i<n;i++)
    {
        if(s[1][i]=='.') s[2][i]='#';
        if(s[7][i]=='.') s[6][i]='#';
    }
    int l=-1;
    int r=-1;
    for(int i=0;i<n;i++)
    {
        if(s[2][i]=='.')
        {
            if(i==0)
            {
                if(s[2][i+1]=='#') l=i; 
                //if(s[6][i+1]=='#') r=i;
                //continue;
            }
            if(i==n-1)
            {
                if(s[2][i-1]=='#') l=i;
                //if(s[6][i-1]=='#') r=i;
                //continue;
            }
            if(i!=0&&s[2][i-1]=='#'||s[2][i+1]=='#') l=i;
        }
        if(s[6][i]=='.')
        {
            if(i==0)
            {
                //if(s[2][i+1]=='#') l=i; 
                if(s[6][i+1]=='#') r=i;
                //continue;
            }
            if(i==n-1)
            {
                //if(s[2][i-1]=='#') l=i;
                if(s[6][i-1]=='#') r=i;
                //continue;
            }
            if(i!=0&&s[6][i-1]=='#'||s[6][i+1]=='#') r=i;
        }
    }
    s[3][l]='#';
    s[5][r]='#';
    if(l==r||l+1==r||r+1==l)
    {
        s[4][l]='#';
    }
    else
    {
        if(l>r)
        {
            int dd=l;
            l=r;
            r=dd;
        }
        for(int i=l+1;i<r;i++)
        {
            s[4][i]='#';
        }
    }
    for(int i=1;i<=7;i++)
    {
       cout<<s[i]<<endl;
    }
}

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