
//#include <atcoder/maxflow.hpp>
#include <memory>
#include <iostream>
#include <map>
#include <list>
#include <set>
#include <algorithm>
#include <vector>
#include <sstream>
#include <string>
#include <functional>
#include <queue>
#include <deque>
#include <stack>
#include <limits>
#include <unordered_map>
#include <unordered_set>
#include <cmath>
#include <fstream>
#include <iterator>
#include <random>
#include <chrono>
#include <complex>
#include <thread>

#define forr(i,start,count) for (int i = (start); i < (start)+(count); ++i)
#define set_map_includes(set, elt) (set.find((elt)) != set.end())
#define readint(i) int i; cin >> i
#define readll(i) ll i; cin >> i
#define readdouble(i) double i; cin >> i
#define readstring(s) string s; cin >> s

typedef long long ll;

using namespace std;
//using namespace atcoder;

ll modd = (1000LL * 1000LL * 1000LL + 7LL);
//ll modd = 998244353;

int main()   {

    ios_base::sync_with_stdio(false);

    cout.precision(17);
    mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
    uniform_int_distribution<int> rand_gen(0, modd);   // rand_gen(rng) gets the rand no

    auto start = chrono::steady_clock::now();

//    readint(test_cases);
    int test_cases = 1;
    forr(t, 1, test_cases) {
        readint(n);
        int ct = 0;
        forr(i,1,n) {
            bool has7 = false;
            int nn = i;
            while (nn>0) {
                if (nn%10==7) {has7=true;}
                nn/=10;
            }
            nn = i;
            while (nn>0) {
                if (nn%8==7) {has7=true;}
                nn/=8;
            }
            if (!has7) {
                ++ct;
            }
        }
        cout << ct << endl;
    }
//        auto stop = chrono::steady_clock::now(); 
//        auto duration = chrono::duration_cast<chrono::milliseconds>(stop - start);
//        cout << "Duration: " << duration.count() << endl;
    return 0;
}


#include <stdio.h>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <list>
#include <queue>
#include <stack>
#include <cmath>
#include <ctime>
#include <cstdio>
#include <vector>
#include <string>
#include <bitset>
#include <cctype>
#include <cstdlib>
#include <cstring>
#include <utility>
#include <numeric>
#include <complex>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <cassert>
#include <iostream>
#include <iterator>
#include <algorithm>
#include <functional>
//#include <atcoder/all>
//using namespace atcoder;
using namespace std;
typedef long long ll;
const double EPS = 1e-9;
typedef vector<int> vint;
typedef vector<vector<int>> v2int;
typedef vector<vector<vector<int>>> v3int;
typedef vector<ll> vll;
typedef vector<vector<ll>> v2ll;
typedef vector<vector<vector<ll>>> v3ll;
typedef list<int> liint;
typedef pair<int, int> pint;
typedef vector<pair<int, int>> vpint;
typedef vector<pair<ll, ll>> vpll;
typedef vector<pair<ll, int>> vpll_int;
typedef vector<pair<int, ll>> vpint_ll;
typedef set<pair<int, int>> spint;
typedef set<pair<ll, int>> spll;
typedef unordered_map<int, unordered_set<int>> Graph;
const int INF = int(2e9);
const ll LINF = ll(2e9) * ll(2e9);
#define rep(i, n) REP(i, 0, n)
#define ALL(v) v.begin(), v.end()
#define MSG(a) cout << #a << " " << a << endl;
#define REP(i, x, n) for(int i = x; i < n; i++)
template<class T, class C> void chmax(T& a, C b) { a > b ? : a = b; }
template<class T, class C> void chmin(T& a, C b) { a < b ? : a = b; }

bool is_seven10(int x) {
    string s = to_string(x);
    rep(i, s.size()) {
        if (s[i] == '7') return true;
    }
    return false;
}

bool is_seven8(int x) {
    while (1) {
        if (x < 8) {
            break;
        }
        int t = x % 8;
        if (t == 7) return true;
        x /= 8;
    }
    if (x == 7) return true;
    return false;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int N;
    cin >> N;

    ll ans = 0;
    REP(x, 1, N + 1) {
        if (is_seven8(x) == true) continue;
        if (is_seven10(x) == true) continue;
        ans++;
    }
    cout << ans << endl;
    return 0;
}