#include<bits/stdc++.h>
using namespace std;
int main(){
	
    string s;
	cin>>s; 
	long long  k=1,ans=0;
	for(int i=s.size()-1;i>=0;i--){
		ans=ans+(s[i]-'0')*k;
		k=k*8;
	}
	cout<<ans;

}



/**************************************************************
	Problem: 1291
	User: zhuangsongyu
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2076 kb
****************************************************************/