#include<bits/stdc++.h>
using namespace std;
#define For(i,a,b) for(int i=(a);i<=(b);i++)
#define Rof(i,a,b) for(int i=(a);i>=(b);i--)
#define wln putchar('\n')
const int N=200005;
int n;
char s1[N],s2[N],ans[7][N];
char inv(char ch){return ch=='.'?'#':'.';}
void Main()
{
    scanf("%d",&n);
    scanf("%s",s1);
    scanf("%s",s2);
    int cnt1=0,p1=-1,cnt2=0,p2=-1;
    For(i,0,n-1)
    {
        cnt1+=s1[i]=='#';
        if(i>0&&s1[i]=='#'&&s1[i-1]=='.')p1=i;
        if(i<n-1&&s1[i]=='#'&&s1[i+1]=='.')p1=i;
    }
    For(i,0,n-1)
    {
        cnt2+=s2[i]=='#';
        if(i>0&&s2[i]=='#'&&s2[i-1]=='.')p2=i;
        if(i<n-1&&s2[i]=='#'&&s2[i+1]=='.')p2=i;
    }
    if(cnt1==n&&cnt2==n)
    {
        printf("Yes\n");
        For(i,0,6)printf("%s\n",s1);
        return;
    }
    if(cnt1==0)
    {
        printf("Yes\n");
        For(i,0,4)printf("%s\n",s1);
        For(i,0,n-1)putchar(inv(s2[i])); wln;
        For(i,0,n-1)putchar(s2[i]); wln;
        return;
    }
    if(cnt2==0)
    {
        printf("Yes\n");
        For(i,0,n-1)putchar(s1[i]); wln;
        For(i,0,n-1)putchar(inv(s1[i])); wln;
        For(i,0,4)printf("%s\n",s2);
        return;
    }
    if(cnt1==n||cnt2==n)
    {
        printf("No\n");
        return;
    }
    printf("Yes\n");
    // printf("p1=%d,p2=%d\n",p1,p2);
    int x=min(p1,p2),y=max(p1,p2);
    For(i,0,n-1)putchar(s1[i]); wln;
    For(i,0,n-1)putchar(inv(s1[i])); wln;
    For(i,0,n-1)putchar(i==p1?'#':'.'); wln;
    if(y-x>1)
    {
        For(i,0,n-1)putchar(i>x&&i<y?'#':'.'); wln;
    }
    else 
    {
        For(i,0,n-1)putchar(i==p1?'#':'.'); wln;
    }
    For(i,0,n-1)putchar(i==p2?'#':'.'); wln;
    For(i,0,n-1)putchar(inv(s2[i])); wln;
    For(i,0,n-1)putchar(s2[i]); wln;
}
int main()
{
    int t;
    scanf("%d",&t);
    while(t--)Main();
}