module B
  sub Main(byval args() as string)
    dim s as string=console.readline()
    dim n,m,l1,m1,l2,m2 as integer
    dim res as boolean = true
    dim cs1,cs2 as string
    n=s.length
    m=math.floor(n/2)
    if left(s,m)=right(s,m) then res=true
    l1=(n-1)/2
    cs1=left(s,l1)
    m1=math.floor(l1/2)
    if res = true andalso left(cs1,m1)<>right(cs1,m1) then res= false
    l2=(n+3)/2
    cs2=s.substring(l2-1)
    m2=math.floor(cs2.length/2)
    if res = true andalso left(cs2,m2)<>right(cs2,m2) then res= false
    console.writeline(if(res,"Yes","No"))
  end sub
end module