#include <bits/stdc++.h>

using namespace std;

void solve()
{
    int n; cin >> n;
    string s1, s2; cin >> s1 >> s2;
    s1 = " " + s1, s2 = " " + s2;

    int pos = 0;
    int cnt1 = 0, cnt2 = 0;
    for (int i = 1; i <= n; i ++ )
    {
        if (s1[i] == '#' && pos == 0) pos = i;
        if (s1[i] == '.') cnt1 ++ ;
        if (s2[i] == '.') cnt2 ++ ;
    }
    if (cnt1 == n || cnt2 == n)
    {
        cout << "Yes\n";
        for (int i = 1; i <= n; i ++ ) cout << s1[i];
        cout << '\n';
        for (int i = 2; i <= 6; i ++ )
        {
            for (int j = 1; j <= n; j ++ )
            {
                cout << '.';
            }
            cout << '\n';
        }
        for (int i = 1; i <= n; i ++ ) cout << s2[i];
        cout << '\n';
        return;
    }
    if (cnt1 == 0 && cnt2 == 0)
    {
        cout << "Yes\n";
        for (int i = 1; i <= 7; i ++ )
        {
            for (int j = 1; j <= n; j ++ )
            {
                cout << '#';
            }
            cout << '\n';
        }
        return;
    }
    if (cnt1 != 0 && cnt2 == 0)
    {
        cout << "No\n";
        return;
    }
    else if (cnt1 == 0 && cnt2 != 0)
    {
        cout << "No\n";
        return;
    }

    vector<vector<char>> g(8, vector<char>(n + 1));

    for (int i = 1; i <= n; i ++ ) g[1][i] = s1[i];
    for (int i = 1; i <= n; i ++ ) g[7][i] = s2[i];

    // 2
    for (int i = 1; i <= n; i ++ )
    {
        if (i < pos) g[2][i] = '.';
        else
        {
            if (s1[i] == '.') g[2][i] = '#';
            else g[2][i] = '.';
        }
    }
    auto check = [&]()
    {
        int cnt = 0;
        for (int i = 1; i <= n; i ++ )
        {
            if (g[2][i] == '.') cnt ++ ;
        }
        if (cnt == n) return true;
        else return false;
    };
    if (check())
    {
        for (int i = 1; i <= n; i ++ ) g[2][i] = g[1][i];
    }

    // 3
    if (g[2][1] == '.' && g[2][2] == '#')
    {
        g[3][1] = '#';
        for (int i = 2; i <= n; i ++ ) g[3][i] = '.';
    }
    else
    {
        g[3][1] = '.';
        for (int i = 2; i <= n; i ++ )
        {
            if (g[2][i] == '#')
            {
                pos = i;
                break;
            }
            g[3][i] = '#';
        }
        for (int i = pos; i <= n; i ++ ) g[3][i] = '.';
    }

    // 4
    g[4][1] = '#';
    for (int i = 2; i <= n; i ++ ) g[4][i] = '.';

    // 5
    g[5][1] = '.';
    for (int i = 2; i <= n; i ++ ) g[5][i] = '#';

    // 6
    for (int i = 1; i <= n; i ++ )
    {
        if (s2[i] == '.')
        {
            g[6][i] = '#';
            g[5][i] = '.';
            if (i == 2) g[5][1] = '#';
        }
        else g[6][i] = '.';
    }
    if (g[6][2] == '#') g[6][1] = '.';

    cout << "Yes\n";
    for (int i = 1; i <= 7; i ++ )
    {
        for (int j = 1; j <= n; j ++ )
        {
            cout << g[i][j];
        }
        cout << '\n';
    }
}

signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);

    int t = 1;
    cin >> t;
    while (t -- )
    {
        solve();
    }
}