#include <iostream>
#include <algorithm>
#include <iomanip>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>
#include <bitset>
#include <cmath>

static const int MOD = 1000000007;
using ll = long long;
using u32 = uint32_t;
using namespace std;


vector<int> v = {2, 7, 7, 23, 23, 47, 47, 167, 167, 359, 359, 839, 839, 1367, 1367, 1847, 1847, 2207, 2207, 3719, 3719, 5039, 5039, 7919, 7919, 10607, 10607, 11447, 11447, 16127, 16127, 17159, 17159, 19319, 19319, 29927, 29927, 36479, 36479, 44519, 44519, 49727, 49727, 54287, 54287, 57119, 57119, 66047, 66047, 85847, 85847, 97967, 97967, 113567, 113567, 128879, 128879, 177239, 177239, 196247, 196247, 201599, 201599, 218087, 218087, 241079, 241079, 273527, 273527, 292679, 292679, 323759, 323759, 344567, 344567, 368447, 368447, 426407, 426407, 458327, 458327, 516959, 516959, 528527, 528527, 537287, 537287, 552047, 552047, 563999, 563999, 573047, 573047, 579119, 579119, 635207, 635207, 657719, 657719, 744767, 744767, 776159, 776159};
int main() {
    int n;
    cin >> n;
    int ans = 0;
    for (auto &&i : v) {
        if(i <= n) ans++;
        else break;
    }
    cout << ans << "\n";
    return 0;
}