3 x 30 reps of ring row + weighted abmat situps + 2 min rest.

Do as many ring rows as you can while maintaining a good form. When you can't go on for more, complete the rest of the reps with weighted abmat situps. You don't need to aim to absolute max reps of ring rows.

Eg, if you can do 16 ring rows, you will do 14 weighted abmat situps to complete the 30 reps set.

You can use as much weight as you like in sit ups, eg. plate.

Extend the arms overhead in the end of each sit up.

In the ring row you should remain strict and maintain the hollow body. As soon as you start to swing with the hip or you can't pull the chest between the rings, move to the sit up! Be honest!