On the boulder with the character "H". Standing start with an undercling left hand and a sloper right hand, traverse to the right on the ledge (without using the horizontal crack above the roof by convention) and exit by a mantle as for Le Papillon.
NB: it is also possible (slightly more difficult) to continue to traverse on the ledge and to exit by the right arete (first known ascent by Renaat Will).
NB: in 2022 a hold broke and the problem is harder now.