So many possible solutions, I didn't count them. Had a couple wrong ones first.

Spoiler: If you get stuck at the end when you have to guess, the 17's go the the corner, and the leftover 1's create diagonal lines from the corners of the boxes. The lines slant in this direction: (not this one: /)

It removed my slash in the previous comment, oops. The diagonal lines slant with the left side up, right side down.