import math
from math import sqrt
import sys
from collections import deque, defaultdict
from heapq import heappop,heappush
from copy import deepcopy

INF=10**18
MOD=10**9+7
MAX=10**5+7

isp=[1]*MAX*5*2
def eratos(n):
  global isp
  isp[0]=isp[1]=0
  for i in range(2, int(sqrt(n)+1)):
    if isp[i]==0: continue
    for j in range(i+i, n+1, i):
      isp[j]=0    

def main():
  global isp
  N=int(input())
  eratos(N*2)

  ans=0
  for r in range(min(N+1, int(sqrt(N*2)+1))):
    if isp[r]==0: continue
    for p in range(N+1):
      if isp[p]==0: continue
      q=r*r-p
      if 0<q<=N and isp[q]==1:
        ans+=1
        
  print(ans)

if __name__=='__main__':
  main()