#include<iostream>
#include<cassert>
using namespace std;
long N;
int pf[1<<20];
int ps[7];
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	for(int i=2;i<1<<20;i++)if(pf[i]==0)
	{
		for(int j=i;j<1<<20;j+=i)pf[j]=i;
	}
	cin>>N;
	long ans=0;
	for(int m=2;;m++)
	{
		long up=(double)N/(2*m);
		int l=m+1,r=(int)min(up,2*m-1L);
		if(l>r)break;
		int pssz=0;
		{
			int v=m;
			while(v%2==0)v/=2;
			while(v>1)
			{
				int p=pf[v];
				ps[pssz++]=p;
				while(v%p==0)v/=p;
			}
		}
		assert(pssz<=6);
		long sum=0;
		for(int i=0;i<1<<pssz;i++)
		{
			int t=1;
			for(int j=0;j<pssz;j++)if(i>>j&1)t*=ps[j];
			int nl=(double)(l+t-1)/t,nr=(double)r/t;
			if(nl%2==0)nl++;
			long nup=(double)up/t;
			long cur=0;
			while(nl<=nr)
			{
				long q=(double)nup/nl;
				int nnl=nr;
				if(nup<q*nr)nnl=(double)nup/q;
				if(nnl%2==0)nnl--;
				//int nnl=(int)min((long)nr,(long)((double)nup/q))+1;
				cur+=q*((nnl-nl)/2+1);
				nl=nnl+2;
			}
			if(__builtin_parity(i))sum-=cur;
			else sum+=cur;
		}
		ans+=sum;
	}
	cout<<ans<<endl;
}