#include<bits/stdc++.h>
#define int long long
using namespace std;
int i,j,n,m,k,l,t,x,y;
string ss,tt;
int pd(string s)
{
    for(int i=0;i<n;i++)
        if(s[i]=='.') return 0;
    return 1;
}
void solve()
{
    cin>>n>>ss>>tt;
    x=pd(ss);y=pd(tt);
    if(x!=y){
        cout<<"No\n";
        return;
    }
    if(x==y&&x==1){
        cout<<"Yes\n";
        for(int i=1;i<=7;i++)
        {
            for(int j=1;j<=n;j++) cout<<"#";
            cout<<"\n";
        }
        return;
    }
    for(int i=2;i<=n;i++) if(i-2>=0&&ss[i-2]=='.'&&ss[i-1]=='#'){
        x=i;break;
    } else if(ss[i-1]=='.'&&ss[i-2]=='#'){
        x=i-1;break;
    }
    for(int i=2;i<=n;i++) if(tt[i-1]=='#'&&tt[i-2]=='.'){
        y=i;break;
    } else if(tt[i-1]=='.'&&tt[i-2]=='#'){
        y=i-1;
        break;
    }
    cout<<"Yes\n";
    cout<<ss<<"\n";
    for(int i=1;i<=n;i++) if(ss[i-1]=='.') cout<<"#";else cout<<".";
    cout<<"\n";
    for(int j=1;j<=n;j++) if(j==x) cout<<"#";else cout<<".";
    cout<<"\n";

    if(abs(x-y)<=1){
        for(int j=1;j<=n;j++) if(j==x) cout<<"#";else cout<<".";
        cout<<"\n";
    } else {
        for(int j=1;j<=n;j++) if(j>=min(x,y)+1&&j<=max(x,y)-1) cout<<"#";else cout<<".";
        cout<<"\n";
    }
    for(int j=1;j<=n;j++) if(j==y) cout<<"#";else cout<<".";
    cout<<"\n";
    for(int j=1;j<=n;j++) if(tt[j-1]=='.') cout<<"#";else cout<<".";
    cout<<"\n";
    cout<<tt<<"\n";
}
signed main()
{
   // freopen("1.in","r",stdin);
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    cin>>t;
    while(t--) solve();
}