Need help with prolog problem.

In Prolog, assume that you have defined the following facts.

mother(M, C). /* M is the mother of C */

father(F, C). /* F is the father of C */

male(X). /* X is male */

female(X). /* X is female */

Write the Prolog rules for:

grandmother(G, X). /* G is a grandmother of X */

sister(S, X). /* S is a sister of X */