#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>

using namespace std;

int main() {
  int N, K;
  cin >> N >> K;
  vector<int> v(N);
  for (int i=0; i<N; i++) {
    cin >> v[i];
  }

  sort(v.begin(), v.end());

  cout << ceil(v[v.size()-1]-v[0]) << endl;
  return 0;
}