Assuming:
I would be starting out with 1 layer of warm weather clothing not including rain gear.
Food not needing to be cooked.
Not hiking in Brown bear country.

1 Water filter
2 Water bottle
3 Tent = Fly Creek 2
4 Fly
5 Pole
6 Sleeping bag
7 One extra top layer or lighter (not sure)
8 Rain jacket
9 Map
10 Compass
11 Backpack

Assuming the map and compass were considered a group safety item and I could add back in a couple items they would be.

1 Lighter or extra top layer
2 Headlight

Hmm. Not so easy but I think that would do it for me.

Edit = So much would depend on where we were going.