def fun(name, TAU, K):
    sps2 = []
    f = open(name, "r")
    sps1 = f.readlines()
    for i in range(len(sps1)):
        sps1[i] = float(sps1[i].replace("\n", ""))
        if i < TAU:
            sps2.append(0)
        else:
            sps2.append(K * sps1[i-TAU])
    return([sps1,sps2])


def fun2(SS1, SS2, TT):
    D = 0
    N = len(SS1)
    SR1 = sum(SS1)/len(SS1)
    SR2 = sum(SS2)/len(SS2)
    for i in range(TT, len(SS1)):
        D+=(SS1[i]-SR1)*(SS2[i-TT]-SR2)
    for i in range(len(SS1)):
        D+=(SS1[i]-SR1)*(SS2[i-TT]-SR2)
    for i in range(len(SS1)):
        D+=(SS1[N-1]-SR1)*(SS2[N-1-TT]-SR2)
    return(D)