#line 1 "main.cpp"

/**
 * @title Template
 */

#include <iostream>
#include <algorithm>
#include <utility>
#include <numeric>
#include <vector>
#include <array>
#include <cassert>

#line 2 "/Users/kodamankod/Desktop/Programming/Library/other/chmin_chmax.cpp"

template <class T, class U>
constexpr bool chmin(T &lhs, const U &rhs) {
  if (lhs > rhs) { lhs = rhs; return true; }
  return false;
}

template <class T, class U>
constexpr bool chmax(T &lhs, const U &rhs) {
  if (lhs < rhs) { lhs = rhs; return true; }
  return false;
}

/**
 * @title Chmin/Chmax
 */
#line 2 "/Users/kodamankod/Desktop/Programming/Library/other/range.cpp"

#line 4 "/Users/kodamankod/Desktop/Programming/Library/other/range.cpp"

class range {
public:
  class iterator {
  private:
    int64_t M_position;

  public:
    constexpr iterator(int64_t position) noexcept: M_position(position) { }
    constexpr void operator ++ () noexcept { ++M_position; }
    constexpr bool operator != (iterator other) const noexcept { return M_position != other.M_position; }
    constexpr int64_t operator * () const noexcept { return M_position; }

  };

  class reverse_iterator {
  private:
    int64_t M_position;
  
  public:
    constexpr reverse_iterator(int64_t position) noexcept: M_position(position) { }
    constexpr void operator ++ () noexcept { --M_position; }
    constexpr bool operator != (reverse_iterator other) const noexcept { return M_position != other.M_position; }
    constexpr int64_t operator * () const noexcept { return M_position; }

  };
  
private:
  const iterator M_first, M_last;

public:
  constexpr range(int64_t first, int64_t last) noexcept: M_first(first), M_last(std::max(first, last)) { }
  constexpr iterator begin() const noexcept { return M_first; }
  constexpr iterator end() const noexcept { return M_last; }
  constexpr reverse_iterator rbegin() const noexcept { return reverse_iterator(*M_last - 1); } 
  constexpr reverse_iterator rend() const noexcept { return reverse_iterator(*M_first - 1); } 

};

/**
 * @title Range
 */
#line 2 "/Users/kodamankod/Desktop/Programming/Library/other/rev.cpp"

#include <type_traits>
#include <iterator>
#line 6 "/Users/kodamankod/Desktop/Programming/Library/other/rev.cpp"

template <class T>
class rev_impl {
public:
  using iterator = decltype(std::rbegin(std::declval<T>()));

private:
  const iterator M_begin;
  const iterator M_end;

public:
  constexpr rev_impl(T &&cont) noexcept: M_begin(std::rbegin(cont)), M_end(std::rend(cont)) { }
  constexpr iterator begin() const noexcept { return M_begin; }
  constexpr iterator end() const noexcept { return M_end; }

};

template <class T>
constexpr decltype(auto) rev(T &&cont) {
  return rev_impl<T>(std::forward<T>(cont));
}

/**
 * @title Reverser
 */
#line 2 "/Users/kodamankod/Desktop/Programming/Library/other/int_operation.cpp"

#include <cstdint>
#include <type_traits>
#include <limits>

template <class T>
constexpr typename std::make_unsigned<T>::type negation_impl(const T x) {
  using unsigned_type = typename std::make_unsigned<T>::type;
  if (x == std::numeric_limits<T>::min()) return static_cast<unsigned_type>(x);
  return static_cast<unsigned_type>(-x);
}

template <class T>
constexpr typename std::enable_if<std::is_unsigned<T>::value && std::is_integral<T>::value, bool>::type
mul_overflow(const T x, const T y, const T z) { return (x == 0 || y == 0) ? false : x > z / y; }

template <class T>
constexpr typename std::enable_if<std::is_signed<T>::value && std::is_integral<T>::value, bool>::type
mul_overflow(const T x, const T y, const T z) {
  if (x == 0 || y == 0) return z < 0;
  using unsigned_type = typename std::make_unsigned<T>::type;
  if (x > 0 && y > 0) return z <= 0 ? true : mul_overflow<unsigned_type>(x, y, z);
  if (x > 0) return z >= 0 ? false : mul_overflow<unsigned_type>(x, negation_impl(y), negation_impl(z));
  if (y > 0) return z >= 0 ? false : mul_overflow<unsigned_type>(negation_impl(x), y, negation_impl(z));
  return mul_overflow<unsigned_type>(negation_impl(x), negation_impl(y), z);
}

template <class T>
constexpr typename std::enable_if<std::is_integral<T>::value, T>::type
isqrt(T x) {
  T ok = 0, ng = std::numeric_limits<T>::max();
  while (ng - ok > 1) {
    const T md = ok + ((ng - ok) >> 1);
    (mul_overflow(md, md, x) ? ng : ok) = md;
  }
  return ok;
}

template <class T>
constexpr typename std::enable_if<std::is_integral<T>::value, T>::type
ipower(T x, uint64_t e) {
  T res = 1;
  while (e > 0) {
    if (e & 1) res *= x;
    e >>= 1;
    if (e > 0) x *= x;
  }
  return res;
}

/**
 * @title Integer Operations
 */
#line 18 "main.cpp"

using i32 = int32_t;
using i64 = int64_t;
using u32 = uint32_t;
using u64 = uint64_t;

constexpr i32 inf32 = (i32(1) << 30) - 1;
constexpr i64 inf64 = (i64(1) << 62) - 1;

int main() {
  std::array<bool, 100> ok{};
  for (auto i: range(0, 100)) {
    ok[i] = true;
    if (i % 3 != 0) {
      ok[i] = false;
      continue;
    } 
    if (i < 10) {
      ok[i] = false;
      continue;
    }
    if (((i / 10) + (i % 10)) % 3 != 0) {
      ok[i] = false;
      continue;
    }
  }
  i32 N;
  std::cin >> N;
  i32 cnt = 0;
  for (auto i: range(0, std::min(N + 1, 100))) {
    if (ok[i]) {
      ++cnt;
    }
  }
  for (auto S: range(0, ipower(4, 9))) {
    i32 num = 0;
    for (auto i: range(0, 9)) {
      num *= 10;
      num += std::vector<i32>{ 0, 3, 6, 9 }[S % 4];
      S /= 4;
    }
    if (num >= 100 && num <= N) {
      ++cnt;
    }
  }
  std::cout << cnt << '\n';
  return 0;
}