module B
  sub Main(byval args() as string)
    dim s as string=console.readline()
    dim n,m,l as integer
    dim res as boolean = true
    dim cs as string
    n=s.length
    m=math.floor(n/2)
    if left(s,m)<>right(s,m) then res=false
    l=(n-1)/2
    cs=left(s,l)
    m=math.floor(l/2)
    if res = true andalso left(cs,m)<>right(cs,m) then res= false
    cs=right(s,l)
    if res = true andalso left(cs,m)<>right(cs,m) then res= false
    console.writeline(if(res,"Yes","No"))
  end sub
end module