#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(ll i=0;i<n;i++)
#define repl(i,l,r) for(ll i=(l);i<(r);i++)
#define per(i,n) for(ll i=(n)-1;i>=0;i--)
#define perl(i,r,l) for(ll i=r-1;i>=l;i--)
#define fi first
#define se second
#define pb push_back
#define ins insert
#define pqueue(x) priority_queue<x,vector<x>,greater<x>>
#define all(x) (x).begin(),(x).end()
#define CST(x) cout<<fixed<<setprecision(x)
#define rev(x) reverse(x);
using ll=long long;
using vl=vector<ll>;
using vvl=vector<vector<ll>>;
using pl=pair<ll,ll>;
using vpl=vector<pl>;
using vvpl=vector<vpl>;
const ll MOD=1000000007;
const ll MOD9=998244353;
const int inf=2e9+1;
const ll INF=4e18;
const ll dy[8]={-1,0,1,0,1,1,-1,-1};
const ll dx[8]={0,-1,0,1,1,-1,1,-1};
template <typename T> inline bool chmax(T &a, T b) {
  return ((a < b) ? (a = b, true) : (false));
}
template <typename T> inline bool chmin(T &a, T b) {
  return ((a > b) ? (a = b, true) : (false));
}
vector<int> dp(5e7+10);
vector<int> cnt(5e7+10);
vector<int> prime;
int main(){
  ll n;cin >> n;
  rep(i,5e7+10)dp[i]=1;
  for(int i=2;i*i<=n;i++){
    if(!dp[i])continue;
    prime.emplace_back(i);
    for(int j=i;j<=n;j+=i){
      dp[j]=0;
    }
  }
  rep(i,5e7+10)dp[i]=i;
  for(auto p:prime){
    //cout << p << endl;
    for(ll j=p*p;j<=n;j+=p*p){
      while(dp[j]%(p*p)==0){
        dp[j]/=p*p;
      }
    }
  }
  for(int i=1;i<=n;i++)cnt[dp[i]]++;
  ll ans=0;
  for(auto p:cnt)ans+=p*p;
  cout << ans << endl;
  //rep(i,100)cout << dp[i] <<" ";cout << endl;
}