If i had to guess, 19 blocks?
If his home is at (0,0) and he goes to (0,6) that’s 6 blocks. Then he goes to (7,6) which is only 7 more blocks since he was already at (0,6), so now he’s at 13 blocks. Lastly, if he goes from (7,6) to (7,0) that would add 6 more blocks making it 19 blocks.
However there wasn’t a picture included so i’m not sure if you would also add the blocks it took him to get home again. If they want you to include him getting home again then the answer would be 26 blocks, if not 19 blocks.