#include <bits/stdc++.h>

#define int long long

void solve() {
    int n;
    std::cin >> n;
    std::string a, b;
    std::cin >> a >> b;

    int cnt_a = 0, cnt_b = 0;

    std::string a1{};
    for (auto& i : a) {
        cnt_a += (i == '#');
        if (i == '#')
            a1.push_back('.');
        else
            a1.push_back('#');
    }
    std::string b1{};
    for (auto& i : b) {
        cnt_b += (i == '#');
        if (i == '#')
            b1.push_back('.');
        else
            b1.push_back('#');
    }

    std::vector<std::string> ans;

    if (cnt_a == n) {
        if (cnt_b == n || cnt_b == 0) {
            std::cout << "Yes" << '\n';
            for (int i = 0; i < 6; i++) std::cout << a << '\n';
            std::cout << b << '\n';

        } else {
            std::cout << "No" << '\n';
        }
        return;
    }

    if (cnt_b == n) {
        if (cnt_a == n || cnt_a == 0) {
            std::cout << "Yes" << '\n';
            for (int i = 0; i < 6; i++) std::cout << a << '\n';
            std::cout << b << '\n';
        } else {
            std::cout << "No" << '\n';
        }
        return;
    }

    if (cnt_a == 0 || cnt_b == 0) {
        std::cout << "Yes" << '\n';
        for (int i = 0; i < 6; i++) std::cout << a << '\n';
        std::cout << b << '\n';
    }

    ans.push_back(a);
    ans.push_back(a1);
    int idx3 = -1, idx5 = -1;
    for (int i = 0; i < n; i++) {
        if (a1[i] == '.') {
            if (i - 1 >= 0 && a1[i - 1] == '#') {
                idx3 = i;
                break;
            }
            if (i + 1 < n && a1[i + 1] == '#') {
                idx3 = i;
                break;
            }
        }
    }
    for (int i = 0; i < n; i++) {
        if (b1[i] == '.') {
            if (i - 1 >= 0 && b1[i - 1] == '#') {
                idx5 = i;
                break;
            }
            if (i + 1 < n && b1[i + 1] == '#') {
                idx5 = i;
                break;
            }
        }
    }

    std::string t{};
    for (int i = 0; i < n; i++) {
        if (i == idx3)
            t.push_back('#');
        else
            t.push_back('.');
    }
    ans.push_back(t);
    t.clear();
    for (int i = 0; i < n; i++) t.push_back('.');
    int l3 = idx3, l5 = idx5;

    if (l3 > l5) std::swap(l3, l5);
    if (l5 - l3 > 1) {
        for (int i = l3 + 1; i < l5; i++) {
            t[i] = '#';
        }
    } else {
        t[l3] = '#';
    }

    ans.push_back(t);
    t.clear();
    for (int i = 0; i < n; i++) {
        if (i == idx5)
            t.push_back('#');
        else
            t.push_back('.');
    }
    ans.push_back(t);
    ans.push_back(b1);
    ans.push_back(b);

    std::cout << "Yes" << '\n';
    for (int i = 0; i < 7; i++) std::cout << ans[i] << '\n';
}

/*
4
4
#..#
.##.
5
##.#.
.#.##
6
######
.####.
27
.######.######.####.#.#####
.####...####..#.......#####
*/

/*
#..#
.##.
.#..
....
#...
#..#
.##.
*/

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

    int t = 1;
    std::cin >> t;

    for (int i = 0; i < t; ++i) {
        solve();
    }

    return 0;
}