#include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<map>
#include<set>
#include<cstdio>
#include<cmath>
#include<numeric>
#include<queue>
#include<stack>
#include<cstring>
#include<limits>
#include<functional>
#include<unordered_set>
#include<iomanip>
#include<cassert>
#include<regex>
#define rep(i,a) for(int i=(int)0;i<(int)a;++i)
#define pb push_back
#define eb emplace_back
using ll=long long;
constexpr ll mod = 1e9 + 7;
constexpr ll INF = 1LL << 50;
 
template<class T> inline bool chmin(T& a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template<class T> inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
using namespace std;

vector< bool > prime_table(int n) {
  vector< bool > prime(n + 1, true);
  if(n >= 0) prime[0] = false;
  if(n >= 1) prime[1] = false;
  for(int i = 2; i * i <= n; i++) {
    if(!prime[i]) continue;
    for(int j = i + i; j <= n; j += i) {
      prime[j] = false;
    }
  }
  return prime;
}


void solve(){
    int n;
    cin>>n;
    int ans=0;
    vector<bool>v=prime_table(n);
    vector<int>vv;
    rep(i,v.size()){
      if(v[i]==true)vv.pb(i);
    }
    for(int i=2;i<=sqrt(2*n);++i){
      if(v[i]==false)continue;
      for(auto x:vv){
        if(i*i-x>n||i*i-x<0)continue;
        if(v[i*i-x]==true)++ans;
      }
    }
    cout<<ans<<"\n";
}
 
int main(){
	ios::sync_with_stdio(false);
    cin.tie(0);
	cout<<fixed<<setprecision(15);
	solve();
	return 0;
}