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

constexpr int maxn = 2e5 + 5;
constexpr int mod = 998244353, g = 3;
int n;

void solve()
{
    cin >> n;
    string s[8];
    cin >> s[1] >> s[7];
    if (s[1] == s[7])
    {
        bool flag = 1;
        for (int i = 0; i < n; i++) if (s[1][i] == '.') {flag = 0; break;}
        if (flag) {cout << "YES" << endl; for (int i = 1; i <= 7; i++) cout << s[1] << endl; return;}
    }
    if (s[1] != s[7]) {
        bool flag = 1;
        for (int i = 0; i < n; i++) if (s[1][i] == '.') {flag = 0; break;}
        if (flag) {cout << "NO" << endl; return;}
        flag = 1;
        for (int i = 0; i < n; i++) if (s[7][i] == '.') {flag = 0; break;}
        if (flag) {cout << "NO" << endl; return;}
    }

    s[1] = ' ' + s[1] + ' ';
    s[7] = ' ' + s[7] + ' ';
    for (int i = 1; i <= n; i++)
        if (s[1][i] == '.') s[2] += '#';
        else s[2] += '.';
    for (int i = 1; i <= n; i++)
        if (s[7][i] == '.') s[6] += '#';
        else s[6] += '.';
    s[2] = ' ' + s[2] + ' ';
    s[6] = ' ' + s[6] + ' ';


    for (int i = 0; i < n; i++)
    {
        s[3] += '.';
        s[4] += '.';
        s[5] += '.';
    }
    s[3] = ' ' + s[3] + ' ';
    s[4] = ' ' + s[4] + ' ';
    s[5] = ' ' + s[5] + ' ';
    int idx, idy;
    for (int i = 1; i <= n; i++)
    {
        if (s[2][i] == '.' && (s[2][i - 1] == '#' || s[2][i + 1] == '#')) {s[3][i] = '#'; idx = i; break;}
    }
    for (int i = 1; i <= n; i++)
    {
        if (s[6][i] == '.' && (s[6][i - 1] == '#' || s[6][i + 1] == '#')) {s[5][i] = '#'; idy = i; break;}
    }
    if (idx > idy) swap(idx, idy);
    if (idx + 1 >= idy) s[4][idx] = '#';
    else for (int i = idx + 1; i < idy; i++) s[4][i] = '#';
    cout << "YES" << endl;
    for (int i = 1; i < 8; i++) {for (int j = 1; j <= n; j++)cout << s[i][j]; cout << endl;}
}

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