#include<bits/stdc++.h>
using namespace std;

#define rep(i,n) for(ll i=0;i<(n);++i)
using ll = long long;
using pll = pair<ll,ll>;
constexpr ll INF = (1LL<<60);
constexpr ll MOD = (1e9+7);
//constexpr ll MOD = (998244353);
template<class T> bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}return 0;}
template<class T> bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}return 0;}
void dump(){cout<<endl;}
template<class T,class... Ts> void dump(T&& h, Ts&&... t){cout<<h<<", ";dump(forward<Ts>(t)...);}
template<class T> istream &operator>>(istream&is,vector<T>&v){for(auto &elemnt:v)is>>elemnt;return is;}
template<class T,class U> istream &operator>>(istream&is,pair<T,U>&p){is>>p.first>>p.second;return is;}
template<class T>vector<T> make_vector(size_t a){return vector<T>(a);}
template<class T, class... Ts>auto make_vector(size_t a, Ts... ts){return vector<decltype(make_vector<T>(ts...))>(a, make_vector<T>(ts...));}

void solve1();void solve2();
int main(){
  solve1();
  return 0;
}

void solve1(){

  ll n;
  cin>>n;

  auto prime_enumration = [](ll n){
    vector<bool> a(n+1,true);
    for(ll p=2;p<=n;++p){
      if(!a[p])continue;
      ll x=p+p;
      while(x<=n){a[x]=false;x+=p;}
    }
    set<ll> primes;
    for(ll p=2;p<=n;++p){
      if(a[p])primes.emplace(p);
    }
    return primes;
  };
  auto square_enum = [](set<ll>const& a,ll n){
    set<ll> suq;
    for(auto const& v:a){
      if(v*v>(*--a.end()+*----a.end()))break;
      suq.insert(v*v);
    }
    return suq;
  };

  auto a = prime_enumration(n);
  auto b = square_enum(a,n);
  
  ll ans = 0;
  for(auto rr:b){
    for(ll p=0;p<=rr;++p){
      ll q=rr-p;
      if(a.find(p)==a.end())continue;
      if(a.find(q)==a.end())continue;
      ans++;
    }
  }
  cout<<(ans)<<endl;

}