| In a directed graph with 22 nodes numbered from 0 to 21: |
| node 0 should be visited before node 16 |
| node 0 should be visited before node 17 |
| node 0 should be visited before node 2 |
| node 0 should be visited before node 9 |
| node 1 should be visited before node 19 |
| node 1 should be visited before node 7 |
| node 1 should be visited before node 17 |
| node 3 should be visited before node 10 |
| node 3 should be visited before node 18 |
| node 3 should be visited before node 20 |
| node 3 should be visited before node 15 |
| node 3 should be visited before node 14 |
| node 4 should be visited before node 2 |
| node 5 should be visited before node 19 |
| node 5 should be visited before node 16 |
| node 5 should be visited before node 7 |
| node 5 should be visited before node 17 |
| node 5 should be visited before node 14 |
| node 5 should be visited before node 4 |
| node 6 should be visited before node 5 |
| node 6 should be visited before node 9 |
| node 7 should be visited before node 14 |
| node 8 should be visited before node 10 |
| node 8 should be visited before node 19 |
| node 8 should be visited before node 15 |
| node 8 should be visited before node 16 |
| node 8 should be visited before node 17 |
| node 8 should be visited before node 14 |
| node 8 should be visited before node 9 |
| node 10 should be visited before node 21 |
| node 10 should be visited before node 6 |
| node 10 should be visited before node 17 |
| node 10 should be visited before node 9 |
| node 11 should be visited before node 21 |
| node 11 should be visited before node 15 |
| node 11 should be visited before node 7 |
| node 11 should be visited before node 17 |
| node 12 should be visited before node 8 |
| node 12 should be visited before node 0 |
| node 12 should be visited before node 17 |
| node 12 should be visited before node 2 |
| node 13 should be visited before node 16 |
| node 13 should be visited before node 14 |
| node 13 should be visited before node 4 |
| node 13 should be visited before node 2 |
| node 14 should be visited before node 4 |
| node 15 should be visited before node 7 |
| node 15 should be visited before node 17 |
| node 15 should be visited before node 14 |
| node 15 should be visited before node 2 |
| node 16 should be visited before node 4 |
| node 16 should be visited before node 9 |
| node 17 should be visited before node 4 |
| node 17 should be visited before node 9 |
| node 18 should be visited before node 6 |
| node 18 should be visited before node 4 |
| node 18 should be visited before node 9 |
| node 19 should be visited before node 4 |
| node 19 should be visited before node 2 |
| node 20 should be visited before node 7 |
| node 20 should be visited before node 14 |
| node 20 should be visited before node 4 |
| node 20 should be visited before node 9 |
| node 21 should be visited before node 15 |
| node 21 should be visited before node 4. |
