Powering the PCI Riser

I have the 1300 watt EVGA G2 power supply which came with 4 8 pin pci power to 6+2 connectors and 2 8 pin pci power to dual 6+2 connectors. And I purchased 6 pci risers 006c. I have 6x zotac 1070 mini graphic cards which take 1 8 pin connector.

So now, I don't have enough power connectors to connect the pci risers for the remaining 4 cards. Do you have any suggestions?