// Kedves számok DP.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include <iostream>
#include <vector>
#include <string>
using namespace std;
int main()
{
    ios_base::sync_with_stdio(false);
    string s;
    cin >> s;
    int l = s.size();
    long long sum = 1;
    for (int i = 1; i < l; i++)
    {
        sum += pow(2, i - 1);
    }
    bool tight = true;
    for (int i = 0; i < l; i++)
    {
        if (i == 0)
        {
            tight = false;
            int d = s[i] - '0';
            if(3<d)
                sum=pow(2, l - i - 1);
            if (d == 3)
                tight = true;
        }
        else
        {
            tight = false;
            int d = s[i] - '0';
            if (0 < d)
            {
                sum += pow(2, l - i - 1);
            }
            if (3 < d)
            {
                sum += pow(2, l - i - 1);
            }
            if (d == 3 or d == 0)
                tight = true;
            if (!tight)
                break;
        }
    }
    if (tight) sum++;
    cout << sum;
}