#include<bits/stdc++.h> using namespace std; int main(){ string s; cin>>s; int ans=0; for(int i=0;i<s.size();i++){ if(s[i] >= '0' && s[i] <= '9') ans=ans*16+s[i]-'0'; else ans=ans*16+s[i]-'a'+10; } cout<<ans<<endl; return 0; }