#include<iostream>
#include<algorithm>
using namespace std;
int main(){
    int n;
    cin>>n;
    int a[1001];
    cin>>a[1];
    int sum = 0;
    for(int i=2;i<=n;i++){
        cin>>a[i];
        sum = max(abs(a[i]-a[i-1]),sum);
    }
    cout<<sum<<endl;
    return 0;
}