def CoverRelations(S):
    #S = NumericalSemigroup(gens)
    A = []
    #print S
    m= min(S.gens)
    Ap = S.AperySet(min(S.gens))
    #Ap.pop(0)
    for i in Ap:
        for j in Ap:
            if (i - j) in S.gens:
                A.append((j%m, i%m))
    Comb = 2*[0]
    Comb[0] = [x%m for x in Ap]
    Comb[1] = A
    Comb[1].extend([(0,x%m) for x in S.gens[1:]])
    #print A
    #if Poset(Comb, cover_relations = True).is_graded() == False:
        #print "ungraded poset"
    #print S
    #return P.plot(figsize= 15)
    return Comb[1]