#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <map>
#include <set>
#include <stdio.h>
#include <cstring>
#include <queue>
#include <stack>
#include <functional>
#include <math.h>
#include <iomanip>
using namespace std;
#define Would
#define you
const int INF = 999999999;
const int MOD = 1e9 + 7;

int n, m, a, ma, mi = INF;
int main() {
	cin >> n >> m;
	for (int i = 0; i < n; ++i) {
		cin >> a;
		ma = max(ma, a);
		mi = min(mi, a);
	}
	cout << ma - mi << endl;
}