#include <bits/stdc++.h> using namespace std; string a; const int o[]={0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15}; int main() { getline(cin,a); int len=a.size(); int sum=0; for(int i=len-1;i>=0;i--) { int x; if(a[i]>='a' && a[i]<='f') x=o[a[i]-'a'+10]; else if(a[i]>='0' && a[i]<='9') x=o[a[i]-'0']; sum+=pow(16,len-i-1)*x; } cout << sum; return 0; }