#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000001

int main(){
	
	int N;
	cin>>N;
	vector<int> p;
	vector<int> np(N+1,-1);
	
	for(int i=2;i<=N;i++){
		if(np[i]==-1){
			p.push_back(i);
			np[i] = i;
		}
		rep(j,p.size()){
			if(p[j]*i>N||p[j]>np[i]){
				break;
			}
			np[p[j]*i] = p[j];
		}
	}
	
	vector<int> cnt(N+1,0);
	cnt[1] = 1;
	
	for(int i=2;i<=N;i++){
		if(np[i]==i){
			cnt[i]++;
		}
		else{
			int T = np[i];
			if(np[i/T]%T==0){
				T = np[i/T]/T;
			}
			else{
				T = np[i/T]*T;
			}
			np[i] = T;
			cnt[T]++;
		}
	}
	
	long long ans = 0LL;
	rep(i,N+1){
		long long t = cnt[i];
		t *= t;
		ans += t;
	}
	
	cout<<ans<<endl;
			
	return 0;
}