#include<bits/stdc++.h>
using namespace std;

using i64 = long long;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int kase;
    cin >> kase;
    while (kase--) {
        int n;
        cin >> n;
        vector<vector<char>> s(7, vector<char>(n, '.'));
        string a, b;
        cin >> a >> b;
        int upfirst = -1, downlast = -1;
        int cnt = 0;
        for (int i = 0; i < n; i += 1) {
            s[0][i] = a[i];
            s[6][i] = b[i];
            cnt += (a[i] == '#');
            cnt += (b[i] == '#');
        }
        if (cnt == 0) {
            for (int i = 0; i < 7; i += 1) {
                cout << a << '\n';
            }
            continue;
        }

        auto chk = [&](string x)->bool{
            for (int i = 0; i < n; i += 1) {
                if (x[i] != '.')return false;
            }
            return true;
        };

        for (int i = 0; i < n; i += 1) {
            if (s[0][i] == '.') {
                s[1][i] = '#';
                if (upfirst == -1) {
                    upfirst = i;
                }
            }
            if (s[6][i] == '.') {
                s[5][i] = '#';
                downlast = i;
            }
        }
        if (upfirst == -1 && downlast == -1) {
            cout << "Yes\n";
            for (int i = 0; i < 7; i += 1) {
                cout << a << '\n';
            }
        } else if (upfirst == -1 && downlast != -1) {
            cout << "No\n";
        } else if (upfirst != -1 && downlast == -1) {
            cout << "No\n";
        } else {
            cout << "Yes\n";
            int l = -1, r = -1;
            for (int i = 0; i < n; i += 1) {
                if (s[1][i] == '.' && l == -1) {
                    if (i - 1 >= 0 && s[1][i - 1] == '#' || i + 1 < n && s[1][i + 1] == '#') {
                        s[2][i] = '#';
                        l = i;
                    }

                }
                if (s[5][i] == '.' && r == -1) {
                    if (i - 1 >= 0 && s[5][i - 1] == '#' || i + 1 < n && s[5][i + 1] == '#') {
                        s[4][i] = '#';
                        r = i;
                    }
                }
            }
            if (l > r) {
                swap(l, r);
            }
            if (l == r) {
                s[3][l] = '#';
            } else if (l == r - 1 ) {
                s[3][l] = '#';
            } else {
                for (int i = l + 1; i < r; i += 1) {
                    s[3][i] = '#';
                }
            }
            for (int i = 0; i < 7; i += 1) {
                for (int j = 0; j < n; j += 1) {
                    cout << s[i][j];
                }
                cout << '\n';
            }
        }
    }

    return 0;
}
/*
4
4
#..#
.##.
5
##.#.
.#.##
6
######
.####.
27
.######.######.####.#.#####
.####...####..#.......#####


5
8
##.#.#.#
.......#
10
###.##.###
#.##..##.#
9
..###....
....#....
9
##...####
....#....
9
##...####
##...####
*/