#include <fstream.h>

long int cmmdc(long int a, long int b)
{ long int r;

	do
	{
		r=a%b;
		a=b;
		b=r;

	}while(r!=0);

	return a;
}

int main(void)
{ long int a[1000000],a1[1000000],i,j,n,p,count=0,c=0;

	n=1000000;
	count=n+n-1;

	for(i=0;i<n;i++)
	 {a[i]=1;
		a1[i]=1;
	 }

	a[0]=a[1]=a1[0]=a1[1]=0;

	for(i=2;i<n;i++)
	 if(a[i]!=0)
		for(p=2*i;p<=n;p=p+i)
		 {a[p]=0;
			a1[p]=0;
		 }

	for(i=2;i<=n;i++)
	 for(j=2;j<i;j++)
		if(a[i]!=0) {c=c+i-2; break;}
				 else
				if(i%j!=0)
				 if(cmmdc(i,j)==1) c++;


	count=count+2*c;


	return 0;
}