print((function (h, l)
	local n = io.stdin:read("*n") io.stdin:read("*n")
	local t = io.stdin:read("*n")
	h, l = t, t
	for _=2,n do
		t = io.stdin:read("*n")
		if t < l then l = t end
		if h < t then h = t end
	end
	return h - l
end)(0, 0))