#include<bits/stdc++.h>

#define ll  long long
#define ull unsigned long long
#define ld long double
#define pii pair<ll,ll>
using namespace std;
#pragma GCC optimize(3)
#define N 600005

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int T;
    cin>>T;
    while(T--)
    {
        ll n;
        cin>>n;
        string a,b;
        cin>>a>>b;
        ll ca=0,cb=0;
        string c,d;
        for(int i=0;i<n;i++)
        {
            if(a[i]=='#') {
                ca++;
                c+='.';
            }
            else c+='#';
            if(b[i]=='#')
            {
                cb++;
                d+='.';
            }
            else d+='#';
        }
        if(ca==n&&cb==n)
        {
            cout<<"Yes"<<endl;
            for(int i=0;i<7;i++)
            {
                cout<<a<<endl;
            }
            continue;
        }
        else if(ca==n||cb==n)
        {
            cout<<"No"<<endl;
            continue;
        }
        ll pa,pb;
        for(int i=0;i<n;i++)
        {
            if(a[i]=='#'&&(i-1>=0&&a[i-1]=='.'||a[i+1]=='.'))
            {
                pa=i;
                break;
            }
        }
        for(int i=0;i<n;i++)
        {
            if(b[i]=='#'&&(i-1>=0&&b[i-1]=='.'||b[i+1]=='.'))
            {
                pb=i;
                break;
            }
        }
        cout<<"Yes"<<endl;
        cout<<a<<endl<<c<<endl;
        for(int i=0;i<n;i++)
        {
            if(i!=pa) cout<<'.';
            else cout<<'#';
        }
        cout<<endl;
        for(int i=0;i<n;i++)
        {
            if(abs(pa-pb)<=1)
            {
                if(i!=pa) cout<<'.';
                else cout<<'#';
            }
            else
            {
                if(i>min(pa,pb)&&i<max(pa,pb))
                {
                    cout<<'#';
                }
                else cout<<'.';
            }
        }
        cout<<endl;
        for(int i=0;i<n;i++)
        {
            if(i!=pb) cout<<'.';
            else cout<<'#';
        }
        cout<<endl<<d<<endl<<b<<endl;
    }
    return 0;
}