Here's my code that runs well on my PC.

#include<iostream>
#include<algorithm>

using namespace std;
main()
{
      string txt;
      string txtRev;
      string tmp;
      int i;
      int com;
      while(cin>>txt){
      i=0;
      do{
        for (int n=i+2;n<txt.length();n++){
            tmp=txt.substr(i,n);
            txtRev=tmp;
            reverse(txtRev.begin(),txtRev.end());
            com= txtRev.compare(tmp);
         if (com==0) break;
         }
         i++;
      }while (com!=0);
      cout<< tmp <<" " <<endl;
      }
}

#include <string>