Last day, a friend of mine proposed me to subscribe to a race, called unionsmarathon, which goes through Norway and Sweden. As usual, I checked the longitudinal profile of the race to see if it wasn't too hard for me[1] . Here is the longitudinal profile :

unionsmarathon profile

It sounded fine for the half marathon. The first 21,1 km seemed not so hard.
Obviously, after subscribing, I discovered, on the norwegian website, that the half marathon will start at the half of the full marathon! Yes, it changes many things... I now know that I will have to climb the himalaya mountain... Will see tomorrow (Saturday 5th of July) if I succeed...

Notes

[1] I already saw races going upward only.