90
The program explanation:
When SM2 is ON, set ON flow S0. When
M0 is ON, set ON flow S10 and S20.
In S10 branch, it runs S10, S11 and S12. Set
on M1 means the S10 branch is finished.
In S20 branch, it runs S20, S21 and S22. Set
on M2 means the S20 branch is finished.
When both branch S10 and S20 end, set on
S30. When S30 end, reset S30.