limit=pow(10,6)

f=[True]*(limit)
for i in range(2,int(limit**0.5)+1):
	if not f[i]: continue
	for j in range(i*i,limit,i):
		if f[j]: f[j]=False

primes=[2,3]
for i in range(5,limit,2):
	if f[i]:
		primes.append(i)
		
print("number of primes:",len(primes))
print("0-100:",primes[:25]) # check 1-100
print("5 last primes",primes[-5:])