Try this.It works fine in my PC.

addnode=137.116.167.42
addnode=137.116.167.52
addnode=191.238.60.17
addnode=191.238.51.28
addnode=191.235.137.239
addnode=191.235.138.12
addnode=23.97.147.78
addnode=23.97.148.49
addnode=138.91.246.228
addnode=138.91.247.22
addnode=supernode.gridcoin.us