20 (more if you can) (normal set up)
20 (more if you can) cross set up (raise your knees and keep it in the air till you do the set up)
20 (more if you can) raise your leg right in the air and try touching your those
20 (more if you can) raise your leg and push a little with your back so your ass had a small push
20 (more if you can) russian set up (sit down, your knees in the air and turn right to left

While you are doing it, do not stop. Doing so will work harder on your belly and will give a better after work fat loosing than doing one and stopping and starting again.

doing this every day, and it will take about 5 minutes, will help trust me! It's not the number but how you do it.