#include <bits/stdc++.h>
using namespace std;

int main(){
  int N;
  cin >> N;
  int a[N+1]
  for(int i=0;i<N+1;i++){
  cin >> a[i];
  }
  
  int max=a[0];
  int min=a[0];

  for(int i=0;i<N+1;l++){
  if(a[i]>a[i+1])max=a[i+1];
  if(a[i]<a[i+1])min=a[i+1];
  }

  cout << max-min << endl;

  return 0;
}
