I recommend the 50cm mint-flavored dental floss.

This is the Mint Sil dental floss sold at Daiso, which offers excellent value for money! The floss thickness is just right, and there is a decent amount, so it lasts a long time, which is great!! I don't even know how many I've used already!! It costs only 1,000 won and is easy to buy! There are instructions and precautions on the back, so you can refer to them. If you have narrow gaps between your teeth, there is a thinner version available, so you can purchase that one!! Choose based on your dental condition!!