zigzackey

# -*- coding: utf-8 -*-

from collections import deque

if __name__ == '__main__':
	n = int(input())
	L = deque()

	for i in range(n):
		cmdline = input().split()

zigzackey

from collections import deque

if __name__ == '__main__':
	n, q = map(int, input().split())

	Q = deque()

	for i in range(n):
		name, time = input().split()
		Q.append([name, int(time)])

zigzackey

def push(x):
	global stack

	stack.append(x)

def pop():
	global stack

	ret = stack.pop()
	return ret

zigzackey

ope = {"+": lambda a, b: b + a,
	   "-": lambda a, b: b - a,
	   "*": lambda a, b: b * a}
stack = []

for c in input().split():
	if c in ope:
		stack.append(ope[c](stack.pop(), stack.pop()))
	else:
		stack.append(int(c))

zigzackey

def insertionSort(A, n, g):
	global cnt

	for i in range(g, n):
		v = A[i]
		j = i - g
		while j >= 0 and A[j] > v:
			A[j + g] = A[j]
			j = j - g
			cnt = cnt + 1

zigzackey

def selectionSort(A, N):
	for i in range(N):
		minj = i
		for j in range(i, N):
			if A[j][1:] < A[minj][1:]:
				minj = j
		if i != minj:
			tmp = A[i]
			A[i] = A[minj]
			A[minj] = tmp

zigzackey

def selectionSort(A, N):
	global cnt

	for i in range(N):
		minj = i
		for j in range(i, N):
			if A[j] < A[minj]:
				minj = j
		if i != minj:
			tmp = A[i]

zigzackey

def bubbleSort(R, N):
	flag = True
	cnt = 0
	while flag == True:
		flag = False
		for j in range(N - 1, 0, -1):
			if R[j] < R[j - 1]:
				tmp = R[j]
				R[j] = R[j - 1]
				R[j - 1] = tmp

zigzackey

if __name__ == '__main__':
	n = int(input())
	R = [int(input()) for i in range(n)]

	minv = R[0]
	maxv = R[1] - R[0]
	for j in range(1, n):
		if (maxv < R[j] - minv):
			maxv = R[j] - minv
		if (R[j] < minv):

zigzackey

import math

def sieve(x):
	prime = [True for i in range(x)]

	for i in range(2, int(math.sqrt(x))):
		if prime[i] == True:
			j = 0
			while i * (j + 2) < x:
				prime[i * (j + 2)] = False