#include <iostream>
#include <algorithm>
#include <iomanip>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <tuple>
#include <cmath>
#include <numeric>
#include <functional>
#include <cassert>

#define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl;
#define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

using namespace std;
typedef long long ll;
using P = pair<int, int>;
map<P, ll> memo;
bool sq[50000001];
int cnt[50000001];

void init(){
    for(int i = 2; i*i <= 50000000; i++){
        int m = i*i;
        for(int j = 1; j*m <= 50000000; j++){
            sq[j*m] = true;
        }
    }
    for(int i = 1; i <= 50000000; i++) cnt[i] = cnt[i-1] + (sq[i] ? 1 : 0);
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << setprecision(10) << fixed;
    init();
    int n; cin >> n;
    ll ans = 0;
    for(int a = 1; a*a <= n; a++){
        for(int b = 1; b*b <= n; b++){
            int p = n/(a*a);
            int q = n/(b*b);
            ans += min(p, q)-cnt[min(p, q)];
        }
    }
    cout << ans << endl;
}