#include<stdio.h>

int a[100][100],n,i,j,k,nr;

int main()
{
	freopen("fractii.in","r",stdin);
	freopen("fractii.out","w",stdout);

	scanf("%d",&n);

	for(i=2;i<=n;i++)
    	a[i][i]=1;

	for(i=1;i<=n;i++)
		for(j=2;j<=n;j++)
		{
			if(j%i==0)
			{
				k=2;
				while(k<=n/i)
				{
					a[i*k][j*k]=1;
					k++;		
                }
            }
        }
    	
    	

	for(i=1;i<=n;i++)
		for(j=1;j<=n;j++)
		if(a[i][j]==0)nr++;

    printf("%d",--nr);
    return 0;
}