program test
implicit none

integer(8) :: n,a,b,i,j
integer(8) :: x(200000),ans=0

read(*,*) n,a,b
read(*,*) (x(i),i=1,n)

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

write(*,*) ans

end program