#include<iostream>#include<fstream>#include<vector>using namespace std;int in[30];int out[30];int n;int v[30];vector<int> edge[27];void dfs(int s){ v[s]=1; for(int i=0;i<edge[s].size();i++) if(v[edge[s][i]]==0) dfs(edge[s][i]);}int ok(int s){ int i; memset(v,0,sizeof(v)); dfs(s); for(i=0;i<26;i++) if(v[i]==0&&edge[i].size()!=0) return 0; return 1;}void read(){// ifstream cin("in.txt"); int i,j,k; cin>>k; char c[1010]; while(k--) { memset(in,0,sizeof(in)); memset(out,0,sizeof(out)); int f=0; cin>>n; for(i=0;i<26;i++) edge[i].clear(); for(i=1;i<=n;i++) { cin>>c; out[c[0]-'a']++; in[c[strlen(c)-1]-'a']++; edge[c[0]-'a'].push_back(c[strlen(c)-1]-'a'); edge[c[strlen(c)-1]-'a'].push_back(c[0]-'a'); } if(!ok(c[0]-'a')) { cout<<"The door cannot be opened."<<endl; continue; } for(i=0;i<26;i++) if(in[i]!=out[i]) { if(in[i]<out[i]) { if(f==0&&in[i]-out[i]==-1) { f=1; } else break; } } if(i<26) cout<<"The door cannot be opened."<<endl; else cout<<"Ordering is possible."<<endl; }}int main(){ read(); return 0;}
