Monophonic MIDI note-off conundrum

I'm fairly new to max so apologies well in advance if this is a time waster. I have tried very hard before resorting to the forums.
I have a monophonic midi keyboard. I want to be able slur notes. To do this i've decided that I want a gate to close only when the most recent midi pitch value to be issued that has a velocity of more than 0 is then given a velocity of 0. The effect being that the most recent pitch to sound won't be silenced if another key that was pressed before it is then released.
At the moment, when key x is press and then y is press before releasing key x, and then key x is released the note-off value overrides key y.
I imagine there's a very easy solution that I'm just not seeing.

I've experimented with the route, select, zlselect, packing and unpacking this and that....This is my more recent attempt at solving it. I'm trying to use a series of sluice messages to differentiate between pitch values with velocities over 0 and and those those that aren't, then, using [if], compare that to the values I'm actually getting from the [notein].