Help reading pattern

I am working on a baby sleeveless sweater dress, it the first time I have done something like this, and am fairly new at patterns and this one has a line I cant understand. I Have been Stockinette stitching for some time with 63 stitchesand the next direction is

Next (Dec) Row (RS): K3 (2,2), (k2tog, k1) 20 (24,27) times - 43 (50,56) sts at the end of this row.

the pattern is for 3 sizes 12 mo 18 mo and child 4 so I get that the info in () like the (2,2) and (24,27) is probably for he larger sizes but I am not sure exactly what I am doing and how I am getting from 63 to 43 stitches in 1 row. my instinct is that I am knitting 3 stitches then knit 2 together knit 1 for the rest of the row but I want to be sure.

Thanks so much!

“my instinct is that I am knitting 3 stitches then knit 2 together knit 1 for the rest of the row but I want to be sure.”

Yes, the k2tog decs a stitch and since you do that 20 times, you have 20 sts less - 63 minuse 20 = 43.