James hurt himself exercising.  The pain subsided after 3 days, but he knew that the injury would take at least 5 times that long to fully heal. After that, he wanted to wait another 3 days before he started working out again.  If he wants to wait 3 weeks after that to start lifting heavy again, how long until he can lift heavy again?
The injury would be fully healed after 3*5=
<gadget id="calculator">3*5</gadget>
<output>15</output>
15 days.
So he would start exercising again in 15+3=
<gadget id="calculator">15+3</gadget>
<output>18</output>
18 days.
He would then wait for 3*7=
<gadget id="calculator">3*7</gadget>
<output>21</output>
21 more days to start lifting heavy again.
That means he needs to wait 18+21=
<gadget id="calculator">18+21</gadget>
<output>39</output>
39 days.

<result>39</result>