almost_prime1

#include <bits/stdc++.h>
using namespace std;

int fact(int n)
{
    int p = 0;
    for(int i = 2; i*i <= n; i++)
    {
        if(n%i == 0)
        {
            p++;
            while(n%i == 0) n/=i;
        }
    }
    if(n > 1) p++;
    return p;
}

int main()
{
    int n, p = 0;
    cin >> n;
    if(n < 6) cout << 0 << endl;
    else if(n >= 6 && n <= 10) cout << 2 << endl;
    else{
        for(int i = 11; i <= n; i++){
            if(fact(i) >= 2) p++;
        }
        cout << p+2 << endl;
    }
    return 0;
}