This is what I did last time:

17 minutes including 8 minute warm up WITH ARMS
3 minutes legs
1 minute rest
3 minutes legs
1 minute rest
2 minutes legs
1 minute rest
1 minute legs
1 minute rest
1 minute legs
1 minute rest
5 minutes cool down with arms

37 minutes - did 22 minutes with arms, 10 minutes legs, 5 minutes rest

20 minutes with arms
7 minutes more without arms

1 minute rest

2 minutes without arms

1 minute rest

2 minutes with arms

1 minute rest

3 minute cool down with arms

34 minutes done: 23 with arms, 11 without - 3 minutes rest.