#include <bits/stdc++.h>

using namespace std;

int main()
{
    string s;
    cin >> s;
    int i = 1;
    while(i < s.size()){
        if(s[i-1] == s[i]){
            s.erase(i-1, 2);
            if( i != 1) i--;
        }
        else i++;
    }
    if(s == "") s = "Empty String";
    cout << s;
    return 0;
}

std::list<char> super_reduced_list(std::list<char> &l) {
    int k = l.size();
    
    for(auto it1 = l.begin(), it2 = ++l.begin();
        (it1 != l.end()) && (it2 != l.end());
        ) {
        if(*it1 == *it2) {
            it2 = l.erase(it1);
            it1 = l.erase(it2);
            it2 = it1;
            it2++;
        } else {
				it1++;
				it2++;
				}
    }
    
    for(char c : l) {
        std::cout << c;
    }
    
    std::cout << std::endl;
    
    if(k == l.size()) {
        return l;
    } else {
        return super_reduced_list(l);
    }
}

string superReducedString(string s) {
    std::list<char> l(s.begin(), s.end());
    super_reduced_list(l);
    
    return (l.empty())? "Empty String" : string(l.begin(), l.end());
}

public static String superReducedString(String s) {
      // Write your code here          
          StringBuilder sb = new StringBuilder(s+"");
          int l = 0;
          while(l<=sb.length()-2){
              if(sb.charAt(l)==sb.charAt(l+1)){
                  String temp = superReducedString(sb.delete(l, l+2).toString());
                  s = temp;
                  // return sb.toString();
              }
              l++;
          }
          if(s=="") return "Empty string";
          return s;
      }

public static string superReducedString(string s)
    {
 string d,e;
            for(int i=0;i<s.Length-1;i++)
            {
               d= s.Substring(i,  1);
                e = s.Substring(i+1, 1);
                if (e == d)
                { 
                    s=s.Remove(i, 2);
                    if (i == 0) i = i - 1;
                    else

                        i = i - 2;
                }
            }
if (s.Length<1) 
{
    s="Empty String";
    }
            return s;
    }