local s = io.read()
local function j(z)
  local n = #z
  for i = 1, n do
    if z:sub(i, i) ~= z:sub(n + 1 - i, n + 1 - i) then
      return false
    end
  end
  return true
end

local s1 = s:sub(1, (#s - 1) // 2)
local s2 = s:sub((#s + 3) // 2, #s)
local f = j(s) and j(s1) and j(s2)
print(f and "Yes" or "No")
