#include<bits/stdc++.h> using namespace std; int main() { string s; cin>>s; reverse(s.begin(),s.end()); int n=s.size(); int sun=0; for(int i=0;i<n;i++) { sun=sun+pow(8,i)*(s[i]-'0'); } cout<<sun; return 0; }

#include<bits/stdc++.h>
using namespace std;
int main()
{
	string s;
	cin>>s;
	reverse(s.begin(),s.end());
	int n=s.size();
	int sum=0;
	for(int i=0;i<n;i++)
	{
		sum=sum+pow(8,i)*(s[i]-'0');
	}
	cout<<sum;
	return 0;
}