import java.io.*;
import java.util.*;
import java.util.stream.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int left = 0;
        int right = 50000000;
        while (right - left > 1) {
            int m = (left + right) / 2;
            if (convert(m) <= n) {
                left = m;
            } else {
                right = m;
            }
        }
        int ans = left - 3;
        for (int i = 12; i <= n && i < 100; i += 3) {
            if (check(i)) {
                ans++;
            }
        }
        System.out.println(ans);
    }
    
    static int[] values = new int[]{0, 3, 6, 9};
    
    static long convert(int x) {
        ArrayDeque<Integer> deq = new ArrayDeque<>();
        while (x > 0) {
            deq.add(x % 4);
            x >>= 2;
        }
        long ans = 0;
        while (deq.size() > 0) {
            ans *= 10;
            ans += values[deq.pollLast()];
        }
        return ans;
    }
    
    static boolean check(int x) {
        return !(x / 10 % 3 == 0 && x % 10 % 3 == 0);
    }
}
class Utilities {
    static String arrayToLineString(Object[] arr) {
        return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n"));
    }
    
    static String arrayToLineString(int[] arr) {
        return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new));
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public int[] nextIntArray() throws Exception {
        return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}