Please choose the correct ending to complete the given sentence: Computers and Electronics: [header] How to make walnut babies [title] Rest the walnut on a cutting board. [title] Use a knife or blade of a strong pair of scissors to insert into the round end of the walnut. [step] This end is the weakest part of the walnut.

Ending1: [title] Place your finger on the center of the walnut's top corner and pinch down on it. [step] This part will not hold its shape while you cut it. Ending2: [substeps] If using your fingers, all you can do is slide the knife between the shell and the walnut. When inserting, keep the knife fully at the edge of the walnut (about 1/4 to 1/8 " from the shell) while you draw your knife across the body. Ending3: The thickest part of the walnut, the inner shell, is the hardest to insert and will break in two. Keep your fingers close to the walnut to prevent it from rolling away. Ending4: [title] Gently tap the walnut on the board. [step] Do this a few times and the prised open end should start to split, leaving the walnut in halves.

Answer format: ending1/ending2/ending3/ending4