Please choose the correct ending to complete the given sentence: Home and Garden: [header] How to apply airstone [title] Calculate how much stone you need. [step] Measure the length and width of the wall or surface that you are covering with stone. Multiply those numbers to find the square footage that you need to buy.

Ending1: This is how much stone you need, and the multiplier will determine how much of it to buy. [substeps] Take the piece of wall you want to cover and multiply the square footage by 15. Ending2: [substeps] For example, if you have a five-sided wall, multiply it by 80 (80 x 80 = 800) to get the square footage that you need. [title] Purchase 3 square feet of stones for every 52 square feet. Ending3: [substeps] Try to purchase enough stone so that you will have enough stones on the wall or surface that are perfect for your painting. Alternately, you can purchase a planed wall to also ensure your square footage. Ending4: Also measure the edges and corners, as these require different stones than the flat surface. [substeps] The majority of the area will be covered in flat stones.

Answer format: ending1/ending2/ending3/ending4