Basically, I'm trying to do something like [highest 1 of {a pool of Xd4, Yd6, Zd8, etc, all together}]

For example:I roll 1d4 and 1d6 and 1d8; their results are, respectively, 4(out of 4 max), 5(out of 6) and 2(out of 8). My end result is 5 here.

How would I do such a thing in AnyDice syntax?