an akari puzzle.
the core theme of this puzzle is placing lights such that 2s don’t suffocate 1s. for instance, at the top of the puzzle, if these two lights are placed:
then the red 1 is suffocated. therefore, we must place a light in the blue cell.
using the same idea, we place the following three lights (the green numbers show the order):
we can repeat the same idea with the two 2s (now 1s, circled in green):
also note that because of the green squares, each of the blue and red lines must have exactly one light in either of their circled positions (i.e. either we place the left blue and the right red, or the right blue and the left red). therefore, no lights can be placed in the Xs. it follows that a light must be placed in the yellow square:
from here, the two green 2s will suffocate each other unless lights are placed in both blue squares.
now in the bottom half of the puzzle, we can place a series of lights after rescuing the red X. in the top half, the two green 1s eliminate most cells on the red and blue lines, and in particular this means the yellow light must be placed:
from here, we can just follow the natural flow of the game:
完成です。