#include <iostream>
using namespace std;
int main()
{
	int n,v[1000],p,r=0;
	cin>>n;
	for (int i=0;i<n;i++)
	{
		cin>>v[i];
		if (i==0) p=v[i];
		else if (v[i]>v[i-1])
		{
			if (v[i]-p>r)
				r=v[i]-p;
		}
		else v[i]=p;
	}

	cout<<r;

	return 0;
}