#include<bits/stdc++.h>
#define int long long
using namespace std;
int Read(){
	int x=0;
	char ch=getchar();bool f=0;
	while(ch<'0'||ch>'9') if(ch=='-')f=1,ch=getchar(); else if(ch==EOF)return 0; else ch=getchar();
	while(ch>='0'&&ch<='9') x=(x<<1)+(x<<3)+(ch^48),ch=getchar();
	return f?-x:x;
}
char s1[100005],s2[100005];
signed main(){
//	freopen(".in","r",stdin);
//	freopen(".out","w",stdout);
	int T=Read();
	while(T--){
		int n=Read();
		scanf("%s",s1);
		scanf("%s",s2);
		bool flag1=1,flag2=2;
		for(int i=0;i<n;i++) {if(s1[i]=='.') flag1=0; if(s2[i]=='.') flag2=0;}
		if(flag1&&flag2){
			printf("Yes\n");
			for(int i=1;i<=7;i++) printf("%s\n",s1);
			continue;
		}if(flag1||flag2){
			printf("No\n");
			continue;
		}printf("Yes\n");
		printf("%s\n",s1);
		for(int i=0;i<n;i++){
			printf("%c",s1[i]=='#'?'.':'#');
		}printf("\n");
		int tar1=200000,tar2=200000;
		for(int i=1;i<n;i++) {
			if(s1[i]!=s1[i-1]) tar1=(s1[i]=='#'?i:i-1);
			if(s2[i]!=s2[i-1]) tar2=(s2[i]=='#'?i:i-1);
		}
		for(int i=0;i<n;i++) if(i==tar1) printf("#"); else printf(".");
		printf("\n");
		if(abs(tar1-tar2)<=1){
			for(int i=0;i<n;i++) if(i==tar1) printf("#"); else printf(".");
		}else{
			for(int i=0;i<n;i++) if(i>min(tar1,tar2)&&i<max(tar1,tar2)) printf("#"); else printf(".");
		}printf("\n");
		for(int i=0;i<n;i++) if(i==tar2) printf("#"); else printf(".");
		printf("\n");
		for(int i=0;i<n;i++){
			printf("%c",s2[i]=='#'?'.':'#');
		}printf("\n");
		printf("%s\n",s2);
	}
	return 0; 
}