#include <iostream>
#include <math.h>

using namespace std;

int main(int argc, char** argv)
{
	unsigned int n; //(3<=n<=9)
	unsigned int k; //(3<=k<=n)
	cin >> n >> k;

	double nums[9];
	double max = 1, min = 1000;
	for (int ii=0; ii<n; ++ii) {
		cin >> nums[ii];
		max = (max<nums[ii]?nums[ii]:max);
		min = (min>nums[ii]?nums[ii]:min);
	}
	cout << ceil(max-min) << endl;

	return 0;
}