Thanks for that tip, so i'll withdraw my post to be sure it wont' stay too long.
=> spoiler removed after cup_of_tea answer. (wasn't a spoiler anyway as it was wrong )
Expectected result : 2178614523.
So my result on this example is really completely different, i don't know where the problem is.
So i someone could have an hint ot some intermediary steps, i'll be gratefull.