#include <bits/stdc++.h>
using namespace std;
int pa[256]={0};//标记边的连通性
int used[256]={0};//某字母是否出现过
int sed[256]={0};//对于某点的出入度
int findset(int x){return pa[x]!=x? pa[x]=findset(pa[x]):x;}
int main()
{
int T;
scanf("%d",&T);
while(T--)
{memset(used,0,sizeof(used));
memset(sed,0,sizeof(sed));
int n;
int cc=26;
for(int i='a';i<='z';i++)
pa[i]=i;//初始化
char word[1009];
scanf("%d",&n);
for(int i=0;i<n;i++)
{
scanf("%s",word);
int c1=word[0];
int c2=word[strlen(word)-1];
used[c1]=used[c2]=1;//该字母出现过
sed[c1]++;
sed[c2]--;//各个字母的度数
int s1=findset(c1);
int s2=findset(c2);
if(s1!=s2){pa[s1]=s2;cc--;}
}
vector<int> que;
for(int i='a';i<='z';i++)
{
if(!used[i])cc--;
else if(sed[i]!=0)
que.push_back(sed[i]);
}
int ok=0;
if(cc==1&&(que.empty()||(que.size()==2&&(que[0]==1||que[0]==-1))))ok=1;
if(ok) printf("Ordering is possible.\n");
else printf("The door cannot be opened.\n");
}
return 0;
}
using namespace std;
int pa[256]={0};//标记边的连通性
int used[256]={0};//某字母是否出现过
int sed[256]={0};//对于某点的出入度
int findset(int x){return pa[x]!=x? pa[x]=findset(pa[x]):x;}
int main()
{
int T;
scanf("%d",&T);
while(T--)
{memset(used,0,sizeof(used));
memset(sed,0,sizeof(sed));
int n;
int cc=26;
for(int i='a';i<='z';i++)
pa[i]=i;//初始化
char word[1009];
scanf("%d",&n);
for(int i=0;i<n;i++)
{
scanf("%s",word);
int c1=word[0];
int c2=word[strlen(word)-1];
used[c1]=used[c2]=1;//该字母出现过
sed[c1]++;
sed[c2]--;//各个字母的度数
int s1=findset(c1);
int s2=findset(c2);
if(s1!=s2){pa[s1]=s2;cc--;}
}
vector<int> que;
for(int i='a';i<='z';i++)
{
if(!used[i])cc--;
else if(sed[i]!=0)
que.push_back(sed[i]);
}
int ok=0;
if(cc==1&&(que.empty()||(que.size()==2&&(que[0]==1||que[0]==-1))))ok=1;
if(ok) printf("Ordering is possible.\n");
else printf("The door cannot be opened.\n");
}
return 0;
}