Both speeds depend on Pressure Altitude and OAT, and are given for the 'One Wing Engine Inoperative'-case, VMCA additionally depends on the flap setting.
For ISA conditions (MSL, 15°C), the speeds are:
VMCG: 139kt
VMCA (flaps 15/slats ext.): 128kt
Both, VMCG and VMCA decrease with higher PA and/or OAT, VMCA increases with lower flap settings and decreases with higher settings.
Regards