#include <bits/stdc++.h>
using namespace std;

using Int = long long;
const char newl = '\n';

template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}
template<typename T> void drop(const T &x){cout<<x<<endl;exit(0);}
template<typename T=Int>
vector<T> read(size_t n){
  vector<T> ts(n);
  for(size_t i=0;i<n;i++) cin>>ts[i];
  return ts;
}

//INSERT ABOVE HERE
const Int MAX = 5e7 + 100;
signed dp[MAX];
signed cnt[MAX];
signed main(){
  cin.tie(0);
  ios::sync_with_stdio(0);

  Int n;
  cin>>n;

  for(Int i=1;i<=n;i++) dp[i]=i;
  for(Int i=2;i*i<=n;i++){
    Int s=i*i;
    for(Int j=s;j<=n;j+=s)
      while(dp[j]%s==0) dp[j]/=s;
  }

  Int ans=0;
  for(Int i=1;i<=n;i++) cnt[dp[i]]++;
  for(Int i=1;i<=n;i++) ans+=1LL*cnt[i]*cnt[i];
  cout<<ans<<newl;
  return 0;
}