"use strict";

var processData = function processData(lines) {
  var s = lines[0];
  var mid = s.length / 2;

  if (s.slice(0, mid) === s.slice(mid + 1)) {
    console.log('Yes');
  } else {
    console.log('No');
  }
};

var i = '';
process.stdin.on('data', function (c) {
  return i += c;
});
process.stdin.on('end', function () {
  var _require = require('os'),
      EOL = _require.EOL;

  var lines = i.split(EOL);
  /*your input text, split by lines*/

  processData(lines);
});
