#include <iostream>
#include <algorithm>

using namespace std;

const int N = 1010;

int a[N];

int main(){

    int n;
    while(cin >> n){

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

        int res = 0;
        for(int i=0,j=0;i<=n;i++){
            j = i+1;
            while(j<n && a[j] >= a[j-1]){   //注意！非下降序列，故取">="
                j++;
            }
            res = max(res,a[j-1] - a[i]);
            i = j-1;   //下一次循环自动i++
        }

        cout << res << endl;
    }

    return 0;
}