#include <iostream>
#include <vector>
#include <math.h>
#include <set>
#include <cstring>
#include <stdio.h>
#include <algorithm>
using namespace std;
void sum(vector <int> &a, vector <int> b);
unsigned long long int pow3(int n)
{
    if (n == 0)
        return 1;
    unsigned long long int a = pow3(n/2);
    if (n&1)
        return 3*a*a;
    return a*a;
}

void print(vector <int> a)
{
    bool bol = 1;
    for (int i = 0; i != 60; i++)
    {
        if (a[i] != 0)
            bol = 0;
        if (!bol)
            printf("%d", a[i]);
    }
    return ;
}

unsigned long long int poww(int n)
{
    if (n <= 0)
        return 0;
    return pow3(n-1)*2;
}

void multiply(vector <int> &a)
{
    int p, peren = 0, i;
    for (i = 59; i >= 0; i--)
    {
        p = (a[i]*2 + peren)/10;
        a[i] = (a[i]*2+peren)%10;
        peren = p;
    }
    return ;
}

vector <int> all(int n)
{
    vector <int> a;
    for (int i = 0; i != 59; i++)
        a.push_back(0);
    a.push_back(1);
    for (int i = 0; i != n; i++)
    {
        multiply(a);
    }
    return a;
}

vector <int> how(char *c, int len)
{
    vector <int> a;
    for (int i = 0; i != 60; i++)
        a.push_back(0);
    if (len == 0)
    {
        a[59] = 1;
        return a;
    }
    if (c[0] < '3')
        return a;
    if (c[0] >= '3')
    {
        if (c[0] == '3')
            sum(a, how(c+1, len-1));
        else
            sum(a, all(len-1));
    }
    if (c[0] >= '7')
    {
        if (c[0] == '7')
            sum(a, how(c+1, len-1));
        else
            sum(a, all(len-1));
    }
    return a;
}

void sum(vector <int> &a, vector <int> b)
{
    int i, peren = 0, p;
    for (i = 59; i >= 0; i--)
    {
        p = (a[i] + b[i] + peren)/10;
        a[i] = (a[i] + b[i] + peren) % 10;
        peren = p;
    }
    return ;
}

int main()
{
    char c[61];
    fgets(c, 61, stdin);
    int len = strlen(c)-1;
    vector <int> a;
    for (int i = 0; i != 59; i++)
        a.push_back(0);
    a.push_back(1);
    for (int i = 0; i != len; i++)
    {
        multiply(a);
    }

    int p, peren = 2;
    for (int i = 59; i >= 0 && peren; i--)
    {
        p = (a[i] - peren) < 0 ? 1 : 0;
        a[i] = (a[i] - peren) < 0 ? 10 +(a[i] - peren) : a[i] - peren;
        peren = p;
    }


    if (len == 0)
    {
        cout << "0";
        return 0;
    }
    if (len == 1)
    {
        int v = 0;
        if (c[0] >= '3')
            v++;
        if (c[0] >= '7')
            v++;
        printf("%d", v);
        return 0;
    }
    if (c[0] >= '3')
    {
        if (c[0] == '3')
            sum(a, how(c+1, len-1));
        else
            sum(a, all(len-1));
    }
    if (c[0] >= '7')
    {
        if (c[0] == '7')
            sum(a, how(c+1, len-1));
        else
            sum(a, all(len-1));
    }
    print(a);
    return 0;
}