This is the most fundamental strategy available for the solving of Akari puzzles. If you make a puzzle having a difficulty level of 1, then
you will be able to solve it completely using only this strategy.
The three cells highlighted in blue draw your attention to the pattern cell containing a 3. This cell requires 3 lamps in its horizontally and
vertically adjacent cells, and only three such cells are available. You have no option but to place a lamp into each of these 3 cells.