int main() {
string input;
while( cin >> N && N ) {
E.clear();
int x, y;
while( cin >> x && x ) {
getline( cin, input );
istringstream is( input );
while( is >> y )
E.push_back( make_pair( x, y ) );
}
int cnt = 0;
for( int i = 1; i <= N; ++i ) {
U.init( N );
for( int j = 0; j < E.size(); ++j )
if( E[j].first != i && E[j].second != i )
U.merge( E[j].first, E[j].second );
if( U.getSets() > 2 )
++cnt;
}
cout << cnt << endl;
}
}
int main() {
int T, N, V;
string S;
int IN[26];
int OUT[26];
Union<26> U;
for( cin >> T; T--; ) {
U.init( 26 );
memset( IN, 0, sizeof( IN ) );
memset( OUT, 0, sizeof( OUT ) );
for( cin >> N; N--; ) {
cin >> S;
int x = S[0] - 'a',
y = S[S.size() - 1] - 'a';
IN[x]++;
OUT[y]++;
U.merge( x, y );
}
bool yes = true;
int cnt = 0;
for( int i = V = 0; i <26; ++i ) {
V += IN[i] || OUT[i];
if( IN[i] == OUT[i] )
continue;
if( IN[i] - OUT[i] > 1 ||
IN[i] - OUT[i] < -1 ) {
yes = false;
break;
}
++cnt;
}
if( cnt > 2 || !yes || U.getSets() + V != 27 ) {
puts( "The door cannot be opened." );
continue;
}
else puts( "Ordering is possible." );
}
}
int main() {
for( cin >> T; T--; ) {
U.init( 26 );
for( int i = 0; i < 26; ++i ) {
G[i].clear();
IN[i] = OUT[i] = 0;
}
for( cin >> N; N--; ) {
string input;
cin >> input;
int x = input[0] - 'a',
y = input[input.size() - 1] - 'a';
IN[x]++;
OUT[y]++;
U.merge( x, y );
G[x].push_back( input );
}
bool yes = true;
int V = 0, cnt = 0;
int begin_pos = 0;
for( int i = 0; i <26; ++i ) {
V += IN[i] || OUT[i];
if( IN[i] == OUT[i] )
continue;
if( IN[i] - OUT[i] > 1 ||
IN[i] - OUT[i] < -1 ) {
yes = false;
break;
}
++cnt;
if( IN[i] - OUT[i] == 1 )
begin_pos = i;
}
// 有两个以上奇度点或者
// 有不平衡点(出入度相差 1 以上) 或者
// 不连通，都判为无欧拉路径
if( cnt > 2 || !yes || U.getSets() + V != 27 ) {
puts( "***" );
continue;
}
// 下面已经确认有欧拉路径，开始寻路
path.clear();
trace.clear();
// 保证字典序
for( int i = 0; i < 26; ++i )
if( G[i].size() > 1 )
sort( G[i].begin(), G[i].end(), greater<string>() );
// 注意如果有一个点 入度 = 出度 + 1
// 必须从这个点开始周游
if( begin_pos == 0 )
while( !IN[begin_pos] && !OUT[begin_pos] )
++begin_pos;
Tour( begin_pos );
cout << path.back();
path.pop_back();
while( path.size() ) {
cout << '.' << path.back();
path.pop_back();
}
cout << endl;
}
}
