#include <bits/stdc++.h>

using namespace std;

int main() {
    int n;
    cin >> n;
    int a[1000] = {0};
    int maxCha = 0;
    for (int i = 1; i < n; i++) {
        cin >> a[i];
        if (abs(a[i] - a[i - 1]) > maxCha) {
            maxCha = abs(a[i] - a[i - 1]);
        }
    }
    cout << maxCha << endl;
    return 0;
}