#include <bits/stdc++.h> 
using namespace std;
#include <ios>
#include <iomanip>
#include <iostream>
#include <string>
#include <algorithm>


int main(void){
  int a,b;
  cin >>a>>b;
  vector<int> vec(a);
  for(int i=0;i<a;i++){
    cin >>vec.at(i);
  }
  int min = *min_element(begin(vec),end(vec));
  int max = *max_element(begin(vec),end(vec));
  cout << max-min;
}