#include<bits/stdc++.h>

#define endl "\n"
// #define int long long

using namespace std;

using i64 = long long;
using u64 = unsigned long long;

constexpr int N = 5e5 + 10, M = 20;
constexpr int P = 1e9 + 7;
constexpr int INF = 1e9;

void solve() {
    int n;
    cin >> n;
    string s1, s2;
    cin >> s1 >> s2;
    auto oppose = [&](char c) {
        if (c == '#') {
            return '.';
        } else {
            return '#';
        }
    };
    if (s1.find('.') == string::npos && s2.find('.') == string::npos) {
        cout << "Yes\n";
        for (int i = 0; i < 7; i++) {
            cout << s1 << endl;
        }
    } else if (s1.find('.') == string::npos || s2.find('.') == string::npos) {
        cout << "No\n";
    } else {
        cout << "Yes\n";
        vector<string> ans(7);
        for (auto &_ : ans) {
            _ = string(n, '.');
        }
        ans[0] = s1;
        ans[6] = s2;
        for (int i = 0; i < n; i++) {
            ans[1][i] = oppose(ans[0][i]);
        }
        for (int i = 0; i < n; i++) {
            ans[5][i] = oppose(ans[6][i]);
        }
        for (int i = 0; i < n - 1; i++) {
            if (ans[1][i] != ans[1][i + 1]) {
                if (ans[1][i] == '.') {
                    ans[2][i] = '#';
                } else {
                    ans[2][i + 1] = '#';
                }
                break;
            }
        }
        for (int i = 0; i < n - 1; i++) {
            if (ans[5][i] != ans[5][i + 1]) {
                if (ans[5][i] == '.') {
                    ans[4][i] = '#';
                } else {
                    ans[4][i + 1] = '#';
                }
                break;
            }
        }
        for (int i = 0; i < n; i++) {
            if (ans[2][i] == ans[4][i] && ans[2][i] == '#') {
                ans[3][i] = '#';
                goto out;
            }
        }
        for (int i = 0; i < n - 1; i++) {
            if (ans[2][i] != ans[4][i] && ans[2][i + 1] != ans[4][i + 1]) {
                ans[3][i] = '#';
                goto out;
            }
        }
        for (int i = 0; i < n; i++) {
            if (ans[2][i] == ans[4][i] && ans[2][i] == '.') {
                ans[3][i] = '#';
            }
        }
out:
        for (const auto &_ : ans) {
            cout << _ << endl;
        }
    }
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int T;
    cin >> T;
    while (T--) {
        solve();
    }
}