Where does “lujakätisesti” come from?

lujakätisesti (Finnish) comes from Finnish lujakätinen, from Finnish -kätinen, from Finnish käsi, from Finnish kahdeksan, from Proto-Finnic kakteksa, from Proto-Finnic kakci, from Proto-Uralic *kakta.

Ancestry of “lujakätisesti”, step by step

Step	Language	Word	Meaning
1	Finnish	lujakätinen	firm-handed
2	Finnish	-kätinen	-handed
3	Finnish	käsi	hand; arm
4	Finnish	kahdeksan	eight
5	Proto-Finnic	kakteksa	eight
6	Proto-Finnic	kakci	two
7	Proto-Uralic	*kakta	—

Every word from Proto-Uralic *kakta →Every word from Proto-Finnic kakci →Every word from Proto-Finnic kakteksa →