#include<bits/stdc++.h>

#define ll long long
#define mk make_pair
#define fi first
#define se second

using namespace std;

inline int read(){
	int x=0,f=1;char c=getchar();
	for(;(c<'0'||c>'9');c=getchar()){if(c=='-')f=-1;}
	for(;(c>='0'&&c<='9');c=getchar())x=x*10+(c&15);
	return x*f;
}

// mt19937 rnd(20070819);
// int randint(int l,int r){return rnd()%(r-l+1)+l;}

void cmax(int &x,int v){x=max(x,v);}
void cmin(int &x,int v){x=min(x,v);}

const int N=2e6+5;
int d[N][26],n,tot,root;
string str[N];
bool isp[N];
vector<int>pf[N],sf[N];
pair<int,int>pos[N];

void solve(){
	cin>>n;
	for(int i=1;i<=n;i++)cin>>str[i];

	root=tot=1;
	for(int i=1;i<=n;i++){
		int p=root;pf[i].resize(str[i].size());
		for(int j=0;j<(int)str[i].size();j++){
			int c=str[i][j]-'a';
			if(!d[p][c]){
				d[p][c]=++tot;
				pos[d[p][c]]=mk(i,j),isp[d[p][c]]=1;
			}
			p=d[p][c],pf[i][j]=p;
		}
	}

	root=++tot;
	for(int i=1;i<=n;i++){
		int p=root;sf[i].resize(str[i].size());
		for(int j=(int)(str[i].size())-1;j>=0;j--){
			int c=str[i][j]-'a';
			if(!d[p][c])pos[d[p][c]=++tot]=mk(i,j);
			p=d[p][c],sf[i][j]=p;
		}
	}

	// cout<<"tot = "<<tot<<endl;

	vector<pair<int,int> >edges;
	vector<int>deg(tot+1);
	auto print=[&](int x){
		// cout<<"print "<<x<<endl;
		auto [p,l]=pos[x];
		if(isp[x])for(int j=0;j<=l;j++)cout<<str[p][j];
		else for(int j=l;j<(int)str[p].size();j++)cout<<str[p][j];
	};
	auto adde=[&](int u,int v){
		// cout<<"adde ";print(u);cout<<" - ";print(v);puts("");
		deg[u]++,deg[v]++,edges.emplace_back(mk(u,v));
	};

	for(int i=1;i<=n;i++){
		for(int j=0;j+1<(int)str[i].size();j++)adde(pf[i][j],sf[i][j+1]);
	}
	for(auto &[u,v]:edges)if(mk(deg[u],u)>mk(deg[v],v))swap(u,v);
	sort(edges.begin(),edges.end());edges.erase(unique(edges.begin(),edges.end()),edges.end());
	// for(int i=0;i<edges.size();i++)for(int j=i+1;j<edges.size();j++)if(edges[i]==edges[j]){
	// 	cout<<"multi edges : ("<<edges[i].fi<<","<<edges[i].se<<")"<<endl;
	// }
	vector<vector<int> >G(tot+1),ind(tot+1);
	for(auto [u,v]:edges)G[u].emplace_back(v),ind[v].emplace_back(u);

	auto clr=[&](){
		for(int i=1;i<=tot;i++)memset(d[i],0,sizeof(d[i])),pos[i]=mk(0,0),isp[i]=0;
		for(int i=1;i<=n;i++)pf[i].clear(),sf[i].clear();
		tot=0;
	};

	// cout<<"tot = "<<tot<<endl;

	auto output=[&](int x,int y,int z,int t,int p=0){
		// cout<<"Case = "<<p<<endl;
		// cout<<"(id) x,y,z,t = "<<x<<" "<<y<<" "<<z<<" "<<y<<endl;
		// cout<<"x,y,z,t = ";print(x),cout<<" ",print(y),cout<<" ",print(z),cout<<" ",print(t),puts("");
		if(!isp[x])swap(x,y);
		if(!isp[z])swap(z,t);
		puts("YES");
		print(x),print(y),cout<<" ",print(z),print(t);puts("");
		print(z),print(y),cout<<" ",print(x),print(t);puts("");
		clr();
	};

	vector<int>vis(tot+1,0);
	for(int i=1;i<=tot;i++){
		// case 1
		for(int j:G[i])for(int k:G[j]){
			// cout<<i<<" -> "<<j<<" -> "<<k<<" vis = "<<vis[k]<<endl;
			if(!vis[k])vis[k]=j;
			else return output(i,j,k,vis[k],1);
		}
		for(int j:G[i])for(int k:G[j])vis[k]=0;

		// case 2
		for(int j:ind[i])for(int k:G[j])if(k!=i)vis[k]=j;
		for(int j:G[i])for(int k:G[j])if(k!=i)if(vis[k])return output(i,j,k,vis[k],2);
		for(int j:ind[i])for(int k:G[j])vis[k]=0;

		// case 3
		for(int j:ind[i])for(int k:G[j])if(k!=i){
			// cout<<j<<" -> "<<i<<" , "<<j<<" -> "<<k<<" vis = "<<vis[k]<<endl;
			if(!vis[k])vis[k]=j;
			else return output(i,j,k,vis[k],3);
		}
		for(int j:ind[i])for(int k:G[j])vis[k]=0;
	}

	puts("NO"),clr();
}

signed main(void){

#ifndef ONLINE_JUDGE
	freopen("2.in","r",stdin);
	freopen("2.out","w",stdout);
#endif

	int tt=read();while(tt--)solve();

	return 0;
}