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You’re going to be increasing at each end of the row. This row shows you where to make the increases using knit front and back (kfb):
Inc row (right side) Kfb, work in pattern to the last 2sts, kfb, k1. Call this row, row 1.
Then the increases will be on rows 7,13,19,25,31,37,43,49,55,61 and 67 for the first two sizes. If you’re working the 3rd size you would continue the increases on rows 73,79,85,91,97 and 103.
All the increases will be on right side (as opposed to wrong side) rows.
Just in case you’d like to see it, here’s a video for kfb: