#include<iostream>
#include<string>
using namespace std;
int main() {
  string s;
  cin >> s;
  bool f = true;
  int i;
  for(i=0;i<s.size()/2;i++) {
    if(s[i] != s[i+s.size()/2+1])f = false;
    if(s[i] != s[s.size()-i-1])f = false;
  }
  if(f)cout << "Yes" << endl;
  else cout << "No" << endl;
}