This Friday we have ... Ken Ken!

Use all the digits from 1-4 (the side length) once each ineach row and column. If there's a -3 in a dark-bordered "cage," the numbers in the cage have a difference of 3 (either 1 and 4 or 4 and 1.) You have to use deductive reasoning to figure out which number goes where.
* 1-4 in each row
* 1-4 in each collumn
* The numbers in each cage have to make the operation true.