lar=input()
lista=map(int,raw_input().split())

def S(lis):
	lis2=[]
	for a in range(len(lis)+1):
		for b in range(len(lis)-a+1):
			c=a+b
			try:
				lis2.append(max(lis[b:c]))
			except:
				pass
	return lis2

print sum(S(S(lista)))