fun main(args: Array<String>) {
	val N = readLine()!!.toInt()
	val K = readLine()!!.toInt()

	val a = mutableListOf(N, 0)

	a.forEachIndexed { i, _ ->
		val n = readLine()!!.toInt()
		a[i] = n
	}

	println(a.max()!! - a.min()!!)
}