#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: hongjiaming
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2076 kb
****************************************************************/