#include <bits/stdc++.h>

using namespace std;
#define ll long long

const int mod = 998244353;

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

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


    int T = 1;
    cin >> T;

    while (T--) {
        solve();
    }
}