#include<iostream>
using namespace std;
int main()
{
    string s;
    while(cin>>s)
    {
        int sum=0;
        int i=2;
        while(s[i]!='\0')
        {
            int d=0;
            if(s[i]=='A')d=10;
            else if(s[i]=='B')d=11;
            else if(s[i]=='C')d=12;
            else if(s[i]=='D')d=13;
            else if(s[i]=='E')d=14;
            else if(s[i]=='F')d=15;
            else{
                d=s[i]-'0';
            }
            sum=sum*16;
            sum+=d;
            i++;
        }
        cout<<sum<<endl;
    }
    return 0;
}