#include<iostream>
#include<algorithm>
#include<cstring>
#include<cmath>

using namespace std;

const int N = 1010;

int n;
int a[N];
int ans = 0;

int main()
{
    cin>>n;
    for(int i = 0; i<n; i++) cin>>a[i];
    for(int i = 1; i<n; i++)
        ans = max(ans,abs(a[i]-a[i-1]));
    cout<<ans;
    return 0;
}