#include <iostream>
using namespace std;
const int N = 1E3 + 10;
int a[N];
int main(){
    int n;  cin >> n;
    for(int i = 0; i < n; i ++ )    cin >> a[i];
    int maxv = 0;
    for(int i = 1; i < n; i ++ )    maxv = max(maxv, abs(a[i] - a[i - 1]));;
    cout << maxv << endl;
    return 0;
}