#include<bits/stdc++.h>

#define N 10000005

#define ll long long

using namespace std;

int mu[N],vis[N],prime[N],cnt;

long long f[N];

void calcmu(){

    cnt=;mu[]=;

    memset(f,,sizeof(f));

    memset(vis,true,sizeof(vis));

    for(int i=;i<N;i++){

        if(vis[i])prime[++cnt]=i,mu[i]=-,f[i]=;

        for(int j=;j<=cnt;j++){

            int t=prime[j]*i;

            if(t>N)break;

            vis[t]=false;

            if(i%prime[j]==){mu[t]=;f[t]=mu[i];break;}

            mu[t]-=mu[i];f[t]=mu[i]-f[i];

        }

    }

    for(int i=;i<=N;i++)f[i]+=f[i-];

}

int read(){

    int f=,x=;char ch;

    do{ch=getchar();if(ch=='-')f=-;}while(ch<''||ch>'');

    do{x=x*+ch-'';ch=getchar();}while(ch>=''&&ch<='');

    return x*f;

}

int main(){

    calcmu();int j;int n,m;

    int T=;

    while(T--){

        ll ans=;n=read();m=n;

        if(n>m)swap(n,m);

        for(int i=;i<=n;i=j+){

            j=n/(n/i);

            ans+=(f[j]-f[i-])*(n/i)*(m/i);

        }

        printf("%lld\n",ans);

    }

    return ;

}