#include <bits/extc++.h>

#ifndef DUMP
#define DUMP(...) (void)0
#endif

using namespace std;

int main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  int n;
  cin >> n;
  int res = 0;
  for (int bt = 0; bt < 1 << 18; ++bt) {
    string s;
    for (int i = 0; i < 9; ++i) s += "0369"[bt >> 2 * i & 3];
    int x = stoi(s);
    res += 100 <= x and x <= n;
  }
  for (int i = 10; i < 100; ++i)
    if (i % 3 == 0) res += i <= n;
  cout << res << '\n';
}