gap> K:=ContractibleGcomplex("SL(2,O-23)");;
gap> R:=FreeGResolution(K,10);;
gap> List([0..9],n->Homology(TensorWithIntegers(R),n));
[ [ 0 ], [ 12, 0, 0, 0 ], [ 2, 2, 12, 0, 0 ], [ 2, 2, 12 ], [ 2, 2, 12 ], 
  [ 2, 2, 12 ], [ 2, 2, 12 ], [ 2, 2, 12 ], [ 2, 2, 12 ], [ 2, 2, 12 ] ]

gap> K:=BianchiGcomplex(-23);;
gap> R:=FreeGResolution(K,10);;
gap> List([0..9],n->Homology(TensorWithIntegers(R),n));
[ [ 0 ], [ 12, 0, 0, 0 ], [ 2, 2, 12, 0, 0 ], [ 2, 2, 12 ], [ 2, 2, 12 ], 
  [ 2, 2, 12 ], [ 2, 2, 12 ], [ 2, 2, 12 ], [ 2, 2, 12 ], [ 2, 2, 12 ] ]