program arc067
    use,intrinsic :: iso_fortran_env
    implicit none
    integer(int32):: n,a,b,i
    integer(int32),allocatable:: x(:)
    integer(int64):: ans=0

    read*, n,a,b
    allocate(x(n))
    read*, x(:)

    do i=2,n
        ans=ans+min(b,a*(x(i)-x(i-1)))
    end do

    print'(i0)', ans
end program arc067