#include <bits/stdc++.h>

typedef long long int64;

int n;
std::string a,b;

void work(){
  std::cin>>n>>a>>b;
  std::vector<int> p,q;
  for (int i=0;i<n;++i){
    if (a[i]=='.') p.push_back(i);
    if (b[i]=='.') q.push_back(i);
  }
  if (p.empty()&&q.empty()){
    std::cout<<"Yes\n";
    for (int i=0;i<7;++i){
      for (int j=0;j<n;++j)
        std::cout<<'#';
      std::cout<<'\n';
    }
    return;
  }
  if (p.empty()||q.empty()){
    std::cout<<"No\n";
    return;
  }
  std::cout<<"Yes\n";
  if ((int)p.size()==n){
    for (int i=0;i<5;++i){
      for (int j=0;j<n;++j)
        std::cout<<'.';
      std::cout<<'\n';
    }
    for (int i=0;i<n;++i)
      std::cout<<(b[i]=='.'?'#':'.');
    std::cout<<b<<'\n';
    return;
  }
  if ((int)q.size()==n){
    std::cout<<a<<'\n';
    for (int i=0;i<n;++i)
      std::cout<<(a[i]=='.'?'#':'.');
    for (int i=0;i<5;++i){
      for (int j=0;j<n;++j)
        std::cout<<'.';
      std::cout<<'\n';
    }
    std::cout<<'\n';
    return;
  }
  std::cout<<a<<'\n';
  for (int i=0;i<n;++i)
    std::cout<<(a[i]=='.'?'#':'.');
  std::cout<<'\n';
  int x=0;
  for (int i=0;i<n;++i)
    if (a[i]=='#'&&((i&&a[i-1]=='.')||(i+1<n&&a[i+1]=='.'))){
      x=i;
      break;
    }
  int y=0;
  for (int i=0;i<n;++i)
    if (b[i]=='#'&&((i&&b[i-1]=='.')||(i+1<n&&b[i+1]=='.'))){
      y=i;
      break;
    }
  for (int i=0;i<n;++i)
    std::cout<<(i==x?'#':'.');
  std::cout<<'\n';
  int l=x,r=y;
  if (l>r) std::swap(l,r);
  if (l+1==r) --r;
  if (l+1<r) ++l,--r;
  for (int i=0;i<n;++i)
    std::cout<<(i>=l&&i<=r?'#':'.');
  std::cout<<'\n';
  for (int i=0;i<n;++i)
    std::cout<<(i==y?'#':'.');
  std::cout<<'\n';
  for (int i=0;i<n;++i)
    std::cout<<(b[i]=='.'?'#':'.');
  std::cout<<'\n';
  std::cout<<b<<'\n';
}

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

  int t=1;
  std::cin >> t;
  while (t--) {
    work();
  }
}

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