void shuchu(char b[], int m)
{
 int i, j, k, l, flag;
 for (j = 2; j <= m; j++)
 {
  for (i = 1; i <= m - 1; i++)
  {
   flag = 1;
   for (k = 0; k < j; k++)
   {
    if (b[i + k] != b[i + j - k - 1])
     flag = 0;
   }
   if (flag)
   {
    for (l = 0; l<j; l++)
    {
     if(l == j-1)
      cout << b[i + l]<<endl;
     else
      cout << b[i + l];
    }
   }
  }
 }
}


int main()
{
 int m;
 char a[501];
 for (m = 1; m > 0; m++)
 {
  if (a[m-1]== '\n')
   break;
  a[m] = cin.get();
 }
 shuchu(a, m);
 return 0;
}

