#include<iostream> #include<bits/stdc++.h> #include <math.h> #include <stdio.h> #include <iostream> #include <string.h> #include <algorithm>#include<bits/stdc++.h> #include<iostream> #include<cmath> #include<map> #include<iomanip> #include<string> #include<cstring> #include<queue> #include <math.h> #include <stdio.h> #include <iostream> #include <string.h> #include <algorithm> using namespace std; string s; int main(){ cin>>s; long c=s.size()-1,ans=0,p=1; { for(int i=c;i>=0;i--) {

int x;
	if(s[i]>='0'&&s[i]<='9')x=s[i]-'0';
	else if(s[i]>='A'&&s[i]<='Z')x=s[i]-'A'+10;
	else x=s[i]-'a'+10;
	ans+=x*p;
	p*=16;
}	}

cout<<ans; return 0; }