Featured Puzzle: Arukone (Number Pairs) #2

Once again, the ancestors seek connection for Dia de los Muertos. This time, they appear in pairs. Connect each pair of skulls with lines, following these restrictions:

• Lines run horizontally or vertically, and may travel straight through a square, or turn 90 degrees.
• Lines may not pass through skull cells, or cross another line.
• No more than one line may pass through any cell.
• A line may not cover a 2×2 area, whether by U-turn, or passing itself.
• All cells will be used.