暴力枚举
#include<string>
#include<cstdio>
#include<iostream>
#include<cstring>
#include<algorithm>
using namespace std;
string s1,s2,s3;
int i,j,k,l,n,v;
bool f;
int main(){
	std::ios::sync_with_stdio(false);
	scanf("%d",&n);
	for(v=1;v<=n;v++){
		i=0;j=0;l=0;f=1;
		cin>>s1>>s2>>s3;
		for(k=0;k<s3.length();k++){
			if(s3[k]==s1[i]&&s3[k]==s2[j]){
				if(i!=s1.length())i++;
		 	 	if(j!=s1.length())j++;
		  		if(i==s1.length()&&j==s2.length())
		  		 break;
		  		l++;
		  		continue;
			}
			else{
				if(l)
			 	 	if(s3[k]==s1[i]&&s3[k]!=s2[j]){
				 	 	i++;
				 	 	j-=l;
				 	 	l=0;
				 	 	continue;
			 		}
			    	else
			      	if(s3[k]==s2[j]&&s3[k]!=s1[i]){
		  		   		j++;
		  				i-=l;
		  				l=0;
		  				continue;
		 			}
				if(s1[i-l]==s3[k]){
		  	    	i=i-l+1;
				 	l=0;
				 	continue;
			 	}
			 	if(s2[j-l]==s3[k]){
			 		j=j-l+1;
					l=0;
			 	    continue;
			 	}
			 	if(s3[k]!=s1[i]&&s3[k]!=s2[j]){
				 f=0;
				 break;
				}
			}
		}
		if(f)printf("Data set %d: yes\n",v);
		else printf("Data set %d: no\n",v);
	}
}