#include <stdio.h>

int main()
{
	int n, p[1001], min = 0, r = 0;
	scanf("%d", &n);
	
	for(int i = 0; i < n; ++i) scanf("%d", &p[i]);
	
	for(int i = 0; i < n-1; ++i)
		if(!(p[i] < p[i+1]) || !(i+1 < n-1))
		{
			if(r < (p[i] - p[min]) && (i+1 < n-1)) r = p[i] - p[min];
			if(r < (p[i+1] - p[min]) && !(i+1 < n-1)) r = p[i+1] - p[min];
			min = i+1;
		}
	
	printf("%d", r);
	
	return 0;
}