#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <queue>
#include <string>
#include <map>
#include <set>
#include <stack>
#include <tuple>
#include <deque>
#include <array>
#include <numeric>
#include <bitset>
#include <iomanip>
#include <cassert>
#include <chrono>
#include <random>
#include <limits>
#include <iterator>
#include <functional>
#include <sstream>
#include <fstream>
#include <complex>
#include <cstring>
#include <unordered_map>
using namespace std;

using ll = long long;
using P = pair<int, int>;
constexpr int INF = 1001001001;
constexpr int mod = 1000000007;
// constexpr int mod = 998244353;

template<class T>
inline bool chmax(T& x, T y){
    if(x < y){
        x = y;
        return true;
    }
    return false;
}
template<class T>
inline bool chmin(T& x, T y){
    if(x > y){
        x = y;
        return true;
    }
    return false;
}

int dp[15][2];

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

    string s;
    cin >> s;
    int n = s.length();
    dp[0][0] = 1;
    for(int i = 0; i < n; ++i){
        int num = s[i] - '0';
        for(int j = 0; j < 2; ++j){
            for(int k = 0; k <= (j ? 9 : num); k += 3){
                dp[i + 1][j | (k < num)] += dp[i][j];
            }
        }
    }
    int ans = dp[n][0] + dp[n][1] - 4;
    for(int x = 12; x <= min(stoi(s), 100); x += 3){
        if(x % 10 % 3 == 0 && x / 10 % 3 == 0)  continue;
        ans += 1;
    }
    cout << ans << endl;

    return 0;
}