n = input()
l = set(range(2,n))
counter = 0
for i in l:
    if n%i == 0:
	print (str(n)+" is not a prime number ")
	counter = 0
	break
    else:
	s = set(range(i,n,i))
	l = l-s
	counter = 1
if counter == 1:
    print (str(n)+" is a prime number")