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

#define int long long
#define endl '\n'
#define ll long long

signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int t;
    cin>>t;
    int ci=0;
    while(t--){
        int n;
        cin>>n;
        string s1,s2;
        cin>>s1>>s2;
        vector<string>s;
        s.push_back(s1);
        int z1=0,z2=0;
        for(int i=0;i<=n-1;i++){
            if(s1[i]=='.'){
                z1++;
            }
            if(s2[i]=='.'){
                z2++;
            }
        }
        string w1="",w2="";
        for(int i=0;i<=n-1;i++){
            if(s1[i]=='.'){
                w1+='#';
            }
            else {
                w1+='.';
            }
        }
        for(int i=0;i<=n-1;i++){
            if(s2[i]=='.'){
                w2+='#';
            }
            else {
                w2+='.';
            }
        }
        if(z1==0&&z2==0){
            cout<<"Yes"<<endl;
            for(int i=0;i<=6;i++){
                cout<<s1<<endl;
            }
            continue;
        }
        if(s1==s2){
            cout<<"Yes"<<endl;
            cout<<s1<<endl;
            for(int i=0;i<=4;i++){
                cout<<w1<<endl;
            }
            cout<<s2<<endl;
            continue;
        }
        if(z1==n){
            cout<<"Yes"<<endl;
            cout<<s1<<endl;
            for(int i=1;i<=5;i++){
                cout<<w2<<endl;
            }
            cout<<s2<<endl;
            continue;
        }
        if(z2==n){
            cout<<"Yes"<<endl;
            cout<<s1<<endl;
            for(int i=1;i<=5;i++){
                cout<<w1<<endl;
            }
            cout<<s2<<endl;
            continue;
        }
        if(z1==0||z2==0){
            cout<<"No"<<endl;
            continue;
        }
        else {
            int wei1=-1,wei2=-1;
            for(int i=0;i<=n-2;i++){
                if(w1[i]=='#'&&w1[i+1]=='.'){
                    wei1=i+1;
                    break;
                }
            }
            for(int i=n-1;i>=1;i--){
                if(wei1!=-1)break;
                if(w1[i]=='#'&&w1[i-1]=='.'){
                    wei1=i-1;
                    break;
                }
            }
            for(int i=0;i<=n-2;i++){
                if(w2[i]=='#'&&w2[i+1]=='.'){
                    wei2=i+1;
                    break;
                }
            }
            for(int i=n-1;i>=1;i--){
                if(wei2!=-1)break;
                if(w2[i]=='#'&&w2[i-1]=='.'){
                    wei2=i-1;
                    break;
                }
            }
            s.push_back(w1);
            string t1="",t2="";
            for(int i=0;i<=n-1;i++){
                if(i==wei1){
                    t1+='#';
                }
                else t1+='.';
            }
            for(int i=0;i<=n-1;i++){
                if(i==wei2){
                    t2+='#';
                }
                else t2+='.';
            }
            if(abs(wei1-wei2)<=1){
               for(int i=1;i<=2;i++){
                  s.push_back(t1);
               }
               s.push_back(t2);
            }
            else {
                string t3="";
                int l1=min(wei1,wei2),l2=max(wei1,wei2);
                s.push_back(t1);
                for(int i=0;i<=n-1;i++){
                    if(i>=l1+1&&i<=l2-1){
                        t3+='#';
                    }
                    else t3+='.';
                }
                s.push_back(t3);
                s.push_back(t2);
            }
            s.push_back(w2);
            s.push_back(s2);
            cout<<"Yes"<<endl;
            for(int i=0;i<=6;i++){
                cout<<s[i]<<endl;
            }
        }
    }
    return 0;
}