Can you give me some step-by-step instructions for this math problem: Martha is knitting winter wear for her 3 grandchildren. They're triplets, so they're all the same size. She wants to make a hat, scarf, sweater, mittens, and socks for each of them. It takes 2 skeins of wool to make a hat, 4 for a scarf, 12 for a sweater, 1 for a pair of mittens, and 2 for a pair of socks. How many skeins of wool will she need to buy?