Bicycle crunches
This exercise works on the sides of your abdomen known as obliques.
Laid down on your back on a flat surface with knees bent such they are at a 90-degree angle to the floor.
after that Keep your palms behind the head, with elbows extended toward the sides. raise your shoulders off the floor as you bring one knee towards your chest and twist it towards the other shoulder. Extend your other leg straight in the air, as if you are riding a bicycle. Repeat the step alternating every shoulder. Begin with fifteen repetitions and step by step increase the number of sets.

Russian twist
Sit on the ground with legs stretched. Bend your knees and keep your feet flat. Keeping your back straight, lean comfortably whereas contracting your ab muscles.
Stretch out your arms in front of you and twist your torso from side to side. to extend the intensity, tap the floor to the right of your hip and then the left side.