#include <iostream>
#include <cstdio>
#include <cstdlib>
using namespace std;

string md5sum(const string &s){
   string cmd = "echo -n " + s + "| md5sum";
   FILE *fp = popen(cmd.c_str(),"r");
   char c[50];
   fscanf(fp,"%s",c);
   fclose(fp);
   return c;
}

int main(){
   string s;
   cin >> s;
   cout << md5sum(md5sum(s)) << endl;
}