#include <bits/stdc++.h>

using namespace std;

void solve() {
    int n;
    cin >> n;
    string a, b;
    cin >> a >> b;
    int anum = 0, bnum = 0;
    string s;
    for (auto x : a) {
        if (x == '#') {
            anum++;
        }
        s += '.';
    }
    for (auto x : b) {
        if (x == '#') {
            bnum++;
        }
    }
    if (anum == n && bnum == n) {
        cout << "Yes\n";
        for (int i = 1; i <= 7; i++) {
            cout << a << "\n";
        }
        return;
    } else if (anum == n || bnum == n) {
        cout << "No\n";
        return;
    }
    cout << "Yes\n";
    vector<string> ans(8);
    ans[1] = a;
    for (int i = 2; i <= 6; i++) {
        ans[i] = s;
    }
    for (int i = 0; i < n; i++) {
        a[i] == '#' ? ans[2][i] = '.' : ans[2][i] = '#';
        b[i] == '#' ? ans[6][i] = '.' : ans[6][i] = '#';
    }
    ans[7] = b;
    int pos1 = 0, pos2 = 0;
    for (int i = 0; i < n - 1; i++) {
        if (ans[2][i] == '.' && ans[2][i + 1] == '#') {
            ans[3][i] = '#';
            pos1 = i;
            break;
        } else if (ans[2][i] == '#' && ans[2][i + 1] == '.') {
            ans[3][i + 1] = '#';
            pos1 = i + 1;
            break;
        }
    }
    for (int i = 0; i < n - 1; i++) {
        if (ans[6][i] == '.' && ans[6][i + 1] == '#') {
            ans[5][i] = '#';
            pos2 = i;
            break;
        } else if (ans[6][i] == '#' && ans[6][i + 1] == '.') {
            ans[5][i + 1] = '#';
            pos2 = i + 1;
            break;
        }
    }
    if (pos1 > pos2) {
        swap(pos1, pos2);
    }
    for (int i = pos1 + 1; i < pos2; i++) {
        ans[4][i] = '#';
    }
    if (pos2 - pos1 <= 1) {
        ans[4][pos1] = '#';
    }
    for (int i = 1; i <= 7; i++) {
        cout << ans[i] << "\n";
    }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int t;
    cin >> t;
    while (t--) {
        solve();
    }
    return 0;
}