function! s:output()
  let this = {'lines': []}

  function! this.append(line) abort
    call add(self.lines, a:line)
  endfunction

  function! this.build() abort
    return join(self.lines, "\n")
  endfunction

  return this
endfunction

function! s:main(input) abort
  let o = s:output()

  let n = str2nr(a:input[0])
  let k = str2nr(a:input[1])
  let n_list = []
  for i in range(n)
    call add(n_list, str2nr(a:input[i + 2]))
  endfor

  call sort(n_list, 'f')
  let r = n_list[-1] - n_list[0]

  call o.append(r)
  return o.build()
endfunction

let s:input = getline(1, '$')
enew
put =s:main(s:input)
2,$print