#include <bits/stdc++.h>

using namespace std;

using ll = long long;

int main() {
  int T;
  cin >> T;
  while (T--) {
    int n;
    cin >> n;
    string s, t;
    cin >> s >> t;

    int chk = (s == string(n, '#')) + (t == string(n, '#'));
    if (chk == 1) {
      cout << "No\n";
      continue;
    }
    cout << "Yes\n";

    if (chk == 2) {
      for (int i = 0; i < 7; ++i) cout << s << "\n";
      continue;
    }

    cout << s << "\n";
    string ss = "", tt = "";
    for (int i = 0; i < n; ++i) ss += ".#"[s[i] != '#'];
    for (int i = 0; i < n; ++i) tt += ".#"[t[i] != '#'];

    cout << ss << "\n";

    int pos1 = -1, pos2 = -1;
    for (int i = 0; i < n; ++i) {
      if (ss[i] == '.' &&
          ((i > 0 && ss[i - 1] == '#') || (i + 1 < n && ss[i + 1] == '#'))) {
        pos1 = i;
        break;
      }
    }
    for (int i = 0; i < n; ++i) {
      if (tt[i] == '.' &&
          ((i > 0 && tt[i - 1] == '#') || (i + 1 < n && tt[i + 1] == '#'))) {
        pos2 = i;
        break;
      }
    }
    string sss = string(n, '.'), ttt = string(n, '.'), st = string(n, '.');
    sss[pos1] = ttt[pos2] = '#';

    cout << sss << "\n";

    if (pos1 == pos2)
      st[pos1] = '#';
    else if (abs(pos1 - pos2) == 1)
      st[pos1] = '#';
    else {
      for (int i = min(pos1, pos2) + 1; i < max(pos1, pos2); ++i) st[i] = '#';
    }

    cout << st << "\n";
    cout << ttt << "\n";
    cout << tt << "\n";
    cout << t << "\n";
  }
  return 0;
}