#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
using namespace std;
#define rep(i,n) for(int i = 0; i < (n); i++)

int main(){
    int n; cin >> n;
    vector<int>a(n);
    int k; cin >> k;
    rep(i,n){ cin >> a[i]; }
    sort(a.begin(),a.end());
    cout << ceil(a[n-1] - a[0]) << endl;
    return 0;
}