Flying tiger pattern tricked me, I can't figure out the start

I don't consider myself a beginner crocheted, I bought this kit from flying tiger because for 6€ it was pretty cheap and I liked the frog. My doubts arises now, I've done before this kind of flat start to work on the round, but stitches are not adding up?

Round 1: 16 chains From the second chain, work round 2: 15 st, (3st), 1 st, 3 st inc, 7 st, 3 st inc, 1 st, (3st) [42]

Maybe I'm just tired... but it's not adding up??

I don't know if I'm supposed to chain 17, or if I should do that last of the 15 stitches, the 3 stitches and the 1 stitch all in the final chain of the 15 working chains.

The pictures are what the pattern is supposed to be and then what i did the first time that resulted in me frogging it like a ciuple of times