C&A Furniture uses a four$-$step process to make its famous wood table:

Process Processing Time $($minutes$)$

Milling $$ table top $10$

Milling $$ table stand $5$

Assembly $15$

Finishing $20$

The milling machine requires a setup time of $30$ minutes to make table tops and a changeover time of $30$ minutes to make table stands. What is the total set up time