#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0;i<((int)(n));i++)
#define reg(i,a,b) for(int i = ((int)(a));i<=((int)(b));i++)
#define irep(i,n) for(int i = ((int)(n)-1);i>=0;i--)
#define ireg(i,a,b) for(int i = ((int)(b));i>=((int)(a));i--)
typedef long long ll;

/*
*/

ll n,a[1000010]={},ans=0;
vector<ll> pl;

void prime_list(ll n,vector<ll>& p){
	ll visited[500010]={};
	reg(i,2,n){
		if(visited[i]==0){
			p.push_back(i);
			reg(j,2,n){
				if(j*i>n)break;
				visited[i*j]=1;
			}
		}
	}
}

void init(){
	cin>>n;
	prime_list(n,pl);
	for(ll r:pl){
		if(r*r>1000000)break;
		// cerr<<r<<endl;
		a[r*r]=r;
	}
}

int main(void){
	init();
	ll m=pl.size();
	// cerr<<m<<endl;
	rep(i,m){
		ll p=pl[i];
		rep(j,i){
			ll q=pl[j];
			if(a[p+q]!=0){
				ans++;
				// cerr<<p<<" "<<q<<" "<<a[p+q]<<endl;
			}
		}
	}
	ans*=2;
	if(n>=2)ans++;//r=2でいける
	cout<<ans<<endl;
	return 0;
}