program echo
    implicit none
    integer(4):: n, i
    character(:), allocatable:: s
    read*, n
    allocate(character(n):: s)
    read*, s
    if (mod(n,2) /= 0) then
        print*, "No"
        stop
    end if

    do i = 1,n/2
        if (s(i:i) /= s(i+n/2:i+n/2)) then
            print*, 'No'
            stop
        end if
    end do
    print*, "Yes"
end program echo