yep, this is the solution.
Franckly I did it yesterday and at that time I found another answer.
I think I made an error because I am trying to repeat what I've done yesterday and I am not able to do so
I've just spent the last hour only on this problem, because yesterday I was so sure I found a way to solve the problem just with 1) ....
I think I made an error at one point but I didnt catch it...my bad
However, I like it...I think people that like maths can understand my meaning, sometimes you think or you feel you are wrong but you want to go as far as you can to be 100% it's wrong...this is for people who like maths, it's like a game sometimes, you just need to found the good key to enter...
thank you again Ian.