#include <stdio.h>
unsigned int prost (unsigned int k)
{
    unsigned int count, i, j, c,l;
        count = 0;
    for (i=2; i<=k;i++)
    {
        for  (j=2; j<i;j++)
        {
            if ((i%j) == 0) break;

        }
        if (j >= i)
        {
            for (c = 2; c <= k; c++)
            {
                for (l = 2; l < i; l++)
                {
                    if ((c%l) == 0) break;

                }
                if (l >= c && (j*l) < k) count++;
            }
        }

    }
    return(count);
}
int main(void)
{
    unsigned int n, res;
    scanf_s("%d", &n);
    res = prost (n);
    printf("%d", res);
    return(0);
}