#include<bits/stdc++.h>
using namespace std;
int main()
{
	int n;
	long long minn,maxn=-1;
	cin>>n>>minn;
	for(int i=2;i<=n;i++)
	{
		long long a;
		cin>>a;
		maxn=max(maxn,a-minn);
		minn=min(a,minn);
	}
	cout<<maxn;
	return 0;
}