#include<bits/stdc++.h>
using namespace std;
int main(){
	char a[30];
	int i,j;
	cin>>a;
	long long s=0,b;
	for(i=0;i<strlen(a);i++){
		b=1;
		for(j=0;j<strlen(a)-i-1;j++) b*=8;
		s+=(a[i]-48)*b;
	}
	cout<<s;
return 0;}

/**************************************************************
	Problem: 1291
	User: fzy001
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/