#include<bits/stdc++.h>
using namespace std;
using ll=long long;
const int N=1e5+10;

void sol(){
    int n; cin>>n;
    string s,t; cin>>s>>t;
    int cnt1=0,cnt2=0;
    for(int i=0;i<n;i++){
        if(s[i]=='#') cnt1++;
        if(t[i]=='#') cnt2++; 
    }

    if(cnt1==n&&cnt2==n){
        cout<<"Yes\n";
        for(int i=0;i<7;i++){
            cout<<s<<"\n";
        }
        return;
    }
    else if(cnt1==n||cnt2==n){
        cout<<"No\n";
        return;
    }
    

    string s1="";
    string t1="";
    for(int i=0;i<n;i++){
        if(s[i]=='.') s1+='#';
        else s1+='.';
        if(t[i]=='.') t1+='#';
        else t1+='.';
    }
    // cout<<s1<<"\n"<<t1<<"\n";
    string s2="";
    string t2="";
    int f1=-1,f2=-1;
    for(int i=0;i<n-1;i++){
        if(s[i]!=s[i+1]&&f1==-1){
            if(s[i]=='#') f1=i;
            else f1=i+1;
        }
        if(t[i]!=t[i+1]&&f2==-1){
            if(t[i]=='#') f2=i;
            else f2=i+1;
        }
    }
    for(int i=0;i<n;i++){
        s2+='.';
        t2+='.';
    }
    s2[f1]='#';
    t2[f2]='#';
    // cout<<s2<<"\n"<<t2;
    string mid(n,'.');
    if(abs(f1-f2)<=1) mid[f1]='#';
    else for(int i=min(f1+1,f2+1);i<max(f1,f2);i++) mid[i]='#';
    cout<<"Yes\n";
    cout<<s<<"\n"<<s1<<"\n"<<s2<<"\n";
    cout<<mid<<"\n";
    cout<<t2<<"\n"<<t1<<"\n"<<t<<"\n";
}



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