#include <iostream>
#include <cstdio>
#include <cstring>
#include <vector>
#include <set>
#include <algorithm>
#include <cmath>

using namespace std;

int n, a[1005], sol;

int main(){
    scanf("%d", &n);
    for (int i=0; i<n; i++)
        scanf("%d", &a[i]);
    for (int i=1; i<n;){
        int first=a[i-1], j=i;
        while(a[j]>a[j-1])
            j++;
        if (j>i){
            sol=max(sol, a[j-1]-a[i-1]);
            i=j+1;
        }
        else
            i++;
    }
    printf("%d\n", sol);
	return 0;
}