#include <iostream> using namespace std; string s; int main() { cin>>s; long long n,m=0; for(int i=0;i<s.size();i++){ if(s[i]>='A'&&s[i]<='F'){ n=s[i]-'A'+10; } else{ n=s[i]-'0'; } m=m*16+n; } cout<<m; return 0; }