#include <iostream>
#include <algorithm>

using namespace std;

const int N = 1010;

int n;
int a[N];

int main()
{
    cin >> n;
    for (int i = 0; i < n; i ++ ) cin >> a[i];

    int res = 0;
    for (int i = 1; i < n; i ++ )
        if (abs(a[i] - a[i - 1]) > res)
            res = abs(a[i] - a[i - 1]);         //遍历求相邻两数之差的最大绝对值

    cout << res << endl;

    return 0;
}