#include <iostream>
#include <cstdio>

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

    cin >> n;
    int nr = 0;
    int mat[50][50];

    for(int i = 1; i <= n; i++)
    {
        for(int j = 1; j <= n; j++)
        {
            for(int x = 2; x; x++)
            {
                if(i*x<=n && j*x<=n)
                {
                    mat[i*x][j*x] = 1;
                    mat[j*x][i*x] = 1;
                }
                else
                    break;
            }
        }
    }

    for(int i = 1; i <= n; i++)
        for(int j = 1; j <= n; j++)
            if(mat[i][j]!=1)
                nr++;

    cout<<nr;
}