#include<bits/stdc++.h>
using namespace std;
string s;
long long c=0,t=1;
int main(){
    cin>>s;
    for(int i=s.size()-1;i>=0;i--){
        c=c+(s[i]-48)*t;
        t=t*8; 
    }
    cout<<c;
    return 0;
}
/**************************************************************
	Problem: 1291
	User: jiangyuanfeng
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2076 kb
****************************************************************/