class SlidingWindowAggretgation:
	def __init__(self, op) -> None:
		self.op = op
		self.front_stack = []
		self.back_stack = []

	def __len__(self) -> int:
		return len(self.front_stack) + len(self.back_stack)

	def __bool__(self) -> bool:
		return len(self) > 0

	def __str__(self) -> str:
		data = [x for x, _ in self.front_stack][::-1] + [x for x, _ in self.back_stack]
		return str(data)

	def append(self, x) -> None:
		fx = x
		if self.back_stack:
			fx = self.op(self.back_stack[-1][1], x)
		self.back_stack.append((x, fx))

	def popleft(self) -> None:
		if not self.front_stack:
			x = fx = self.back_stack.pop()[0]
			self.front_stack.append((x, fx))
			while self.back_stack:
				x = self.back_stack.pop()[0]
				fx = self.op(x, fx)
				self.front_stack.append((x, fx))
		self.front_stack.pop()

	def all_prod(self):
		res = None
		if self.front_stack:
			res = self.front_stack[-1][1]
		if self.back_stack:
			if res is None:
				res = self.back_stack[-1][1]
			else:
					res = self.op(res, self.back_stack[-1][1])
		return res


def op(a, b):
	m11, m12, M1 = a
	m21, m22, M2 = b
	if m11 < m21:
		n1 = m11
		n2 = min(m21, m12)
	else:
		n1 = m21
		n2 = min(m11, m22)
	return (n1, n2, max(M1, M2))

n = int(input())
a = list(map(int, input().split()))
INF = 10 ** 18
ans = 0
SWAG = SlidingWindowAggretgation(op)
ans = 0
r = 0
def ok(r):
	m1, m2, M = SWAG.all_prod()
	return max(M, a[r]) <= m1 + min(m2, a[r])
for l in range(n):
	while l == r or (r < n and ok(r)):
		SWAG.append((a[r], INF, a[r]))
		r += 1
	ans += r - l - 1
	SWAG.popleft()
print(ans)