import numpy as np
import scipy as sc




def pierwsze(n):
    poczatek = 2;
    a = np.arange(2,n+1,1)
    b = np.array(a)
    print(b);
    for x in b:

        if x%2 == 0:
            if x!=2:
                b[(x-poczatek)] = 0
        elif x%3 == 0:
            if x!=3:
                 b[(x-poczatek)] = 0
    tmp = (np.mod(b,3)!=0)

    print(b[tmp])
n = 20
pierwsze(n)