#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
#define pb push_back
#define mp make_pair
#define rep(i,n) for(int i=0;i<(n);++i)
constexpr int mod=1000000007;
constexpr int mod1=998244353;
vector<int> dx={0,-1,0,1},dy={1,0,-1,0};
bool inside(int y,int x,int h,int w){
	if(y<h && y>=0 && x<w && x>=0) return true;
	return false;
}


vector<bool> prime(1000001,true);
void era(){
	prime.at(0)=false;
	prime.at(1)=false;
	for(int i=2;i<=1000000;++i){
		if(prime.at(i)){
			for(int j=i+i;j<=1000000;j+=i) prime.at(j)=false;
		}
	}
}


int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);
	era();
	int n;cin >> n;
	int ans=0,m=2*n;
	for(int r=2;r*r<=m;++r){
		if(!prime.at(r)) continue;
		int R=r*r;
		for(int p=2;p<=n;++p){
			if(p>=R) break;
			if(!prime.at(p)) continue;
			if(R-p>n) continue;
			if(prime.at(R-p)) ans++;
		}
	}
	cout << ans << endl;
}