Daily challange

Question 1

Captain Aliyev planned to swim out of Pasxi Island and back, navigating all the islands shown on the map. The total length of the journey is 100km. If you are swimming via the Volcano Island, the distance between the Desert and Lake Islands is equal to the distance between Pasxi and Flower Islands. If he/she swims directly, how many kilometers is the distance between Pasxi and Lake Islands?