// yukicoder No.739
#include <bits/stdc++.h>
using namespace std;

int main()
{
  string s; cin >> s;

  int len = s.size() / 2;
  string t = s.substr(0, len);
  string u = s.substr(len);

  cout << t << "\n";
  cout << u << "\n";

  if(t.compare(u) == 0) cout << "YES" << "\n";
  else cout << "NO" << "\n";

  return 0;
	
}