import sys
sys.stdin = open("section2/num_of_prime_num/in5.txt", "rt")

n = int(input())
ch = [0] * (n+1)
cnt = 0
for i in range(2, n+1):
  if ch[i] == 0:
    cnt += 1
    for j in range(i, n+1, i):
      ch[j] = 1
print("%d; # of prime number %d" %(n, cnt) )

679a477885b69ef4b6d613346f330f328c7ad160
<mask token>

<mask token>
for i in range(2, n + 1):
    if ch[i] == 0:
        cnt += 1
        for j in range(i, n + 1, i):
            ch[j] = 1
print('%d; # of prime number %d' % (n, cnt))

<mask token>
sys.stdin = open('section2/num_of_prime_num/in5.txt', 'rt')
n = int(input())
ch = [0] * (n + 1)
cnt = 0
for i in range(2, n + 1):
    if ch[i] == 0:
        cnt += 1
        for j in range(i, n + 1, i):
            ch[j] = 1
print('%d; # of prime number %d' % (n, cnt))

import sys
sys.stdin = open('section2/num_of_prime_num/in5.txt', 'rt')
n = int(input())
ch = [0] * (n + 1)
cnt = 0
for i in range(2, n + 1):
    if ch[i] == 0:
        cnt += 1
        for j in range(i, n + 1, i):
            ch[j] = 1
print('%d; # of prime number %d' % (n, cnt))

import sys
sys.stdin = open("section2/num_of_prime_num/in5.txt", "rt")

n = int(input())
ch = [0] * (n+1)
cnt = 0
for i in range(2, n+1):
  if ch[i] == 0:
    cnt += 1
    for j in range(i, n+1, i):
      ch[j] = 1
print("%d; # of prime number %d" %(n, cnt) )
