Stupid 3-way SLI question: can my mobo do it?

It’s a Z87-A. I have 3 GTX 780s sitting here on my desk.

https://www.asus.com/ca-en/Motherboards/Z87A/ is the mobo.

hmm, only 16 PCIE lanes, I don’t think so.

I’m gonna go with 2-way SLI only.

Specs:
2 x PCIe 3.0/2.0 x16 (x16 or dual x8)
1 x PCIe 2.0 x16 (x2 mode)
2 x PCIe 2.0 x1
2 x PCI

Supports NVIDIA® Quad-GPU SLI™ Technology *2
Supports AMD Quad-GPU CrossFireX™ Technology

*2: With 2 PCIex16 graphics card.

I am going to guess the third PCIe x16 lane is not supported for SLI on this mobo.