data/problems/86.yml
---
:id: 86
:name: Cuboid route
:url: https://projecteuler.net/problem=86
:content: "A spider, S, sits in one corner of a cuboid room, measuring 6 by 5 by 3,
and a fly, F, sits in the opposite corner. By travelling on the surfaces of the
room the shortest \"straight line\" distance from S to F is 10 and the path is shown
on the diagram.\n\n ![]({{ images_dir }}/p086.gif) \n\nHowever, there are up to
three \"shortest\" path candidates for any given cuboid and the shortest route doesn't
always have integer length.\n\nIt can be shown that there are exactly 2060 distinct
cuboids, ignoring rotations, with integer dimensions, up to a maximum size of M
by M by M, for which the shortest route has integer length when M = 100. This is
the least value of M for which the number of solutions first exceeds two thousand;
the number of solutions when M = 99 is 1975.\n\nFind the least value of M such that
the number of solutions first exceeds one million.\n\n"