def main():
    def comb(a,b):
        return fac[a]//fac[b]//fac[a-b]
    fac=[1]
    for x in range(1,7):
        fac.append(fac[-1]*x)

    n=int(input())
    if n<6:
        print(0)
        exit()
    ans=sum(pow(k/6,n)*comb(6,k)*(-1)**k for k in range(1,7))
    print(ans)

main()