#include<bits/stdc++.h>
//giatri
 long long n,e=0,kq=0,bien=0;
 bool ktra[100000];
//giatri 
using namespace std;

int main()
{
 ios_base::sync_with_stdio(false); 
 cin.tie(NULL); 
 cout.tie(NULL);
 
freopen("BEAUNUM.inp","r",stdin);
freopen("BEAUNUM.out","w",stdout);
   memset(ktra,true,sizeof(ktra));
 ktra[0]=ktra[1]=false;
 for(int i=2;i*i<=1e5+5;i++)
 {
  if (ktra[i])
   for (int j=i*i;j<=1e5+5;j+=i)
   {
    ktra[j]=false;
}
  }
 cin>>n;
 
 
 while (bien<n)
 {
  e++;
  if (ktra[e])
  {
   bien=e*e*e*e;
   kq++;
  }
 }
 if (bien>n) 
 {
 kq--;
 }
 
 
 cout<<kq;
 
 
 return 0;
}