Draw a loop, landing on each square exactly once. You may only jump to a square exactly 2 squares in a horizontal or vertical direction, or 2 squares in one direction and 1 square in a perpendicular direction (like a knight in chess). You may jump over missing squares in the grid.

1. | 2. | 3. | 4. | 5. |

6. | 7. | 8. | 9. | 10. |

11. | 12. | 13. | 14. | 15. |

16. | 17. | 18. | 19. | 20. |

The solutions are here.