if __name__=='__main__':
    num = int(input(":pick a number:"))
    if num <= 1 :
        print(" chose another number ")
        exit()
        pn_flag = 0
    for int in range (2,int(num/2)  +1):
      if num % int == 0:
       pn_flag = 1
       break
if pn_flag == 1:
   print("{}   not a prime number".format(num))
else:
   print("{}  is a prime number".format(num))