#include<bits/stdc++.h>
using namespace std;
string s;
long long c,t=1,a[1000]; 
int main(){
	cin>>s;
	for(int i=0;i<s.size();i++){
		a[s.size()-1-i]=s[i]-'0';
	}
	for(int i=0;i<s.size();i++){
		c=c+a[i]*t;
		t=t*8;
	}
	cout<<c;
	return 0;
}

/**************************************************************
	Problem: 1291
	User: zengyixuan
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2084 kb
****************************************************************/