#include <iostream>
#include <algorithm>
#include <vector>

constexpr int D = 9;

void solve() {
    int n;
    std::cin >> n;

    int ans = 0;
    for (int b = 0; b < (1 << D * 2); ++b) {
        int c = b, x = 0;
        for (int i = 0; i < D; ++i) {
            x = x * 10 + (c % 4 * 3);
            c /= 4;
        }
        if (10 <= x && x <= n) ++ans;
    }

    for (int x = 12; x <= 99; x += 3) {
        if ((x % 10) % 3 == 0) continue;
        if (x <= n) ++ans;
    }

    std::cout << ans << "\n";
}

int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    solve();

    return 0;
}