program main
    implicit none
    
    integer :: n, k
    integer :: m
    
    integer :: minimum = 1000, maximum = 1
    
    integer :: i
    
    read *, n
    read *, k
    
    do i = 1, n
        read *, m
        minimum = min(minimum, m)
        maximum = max(maximum, m)
    end do
    
    print '(I0)', maximum - minimum
end program main