from collections import deque
class SWAG:
    def __init__(self, operator_M, e_M):
        self.op_M = operator_M
        self.e_M = e_M
        self.q = deque()
        self.accL = deque([e_M])
        self.accR = e_M
        self.L = self.R = 0

    def build(self,lst):
        self.q = deque(lst)
        self.L = len(lst)
        for i in lst[::-1]:
            self.accL.append(self.op_M(i,self.accL[-1]))

    def __len__(self):
        return self.L + self.R

    def fold_all(self):
        return self.op_M(self.accL[-1],self.accR)

    def append(self,x):
        self.q.append(x)
        self.accR = self.op_M(self.accR,x)
        self.R += 1
    
    def popleft(self):
        if self.L:
            self.accL.pop()
            self.L -= 1
            return self.q.popleft()
        elif self.R:
            v = self.q.popleft()
            self.L,self.R = self.R-1,0
            for i in reversed(self.q):
                self.accL.append(self.op_M(i,self.accL[-1]))
            self.accR = self.e_M
            return v
        else:
            assert 0


n = int(input())
*a, = map(int,input().split())

def f(A,B):
    a,b,m1 = A
    c,d,m2 = B
    if a < c: return (a,min(c,b),max(m1,m2))
    else: return (c,min(a,d),max(m1,m2))

INF = 1<<60
swag = SWAG(f,(INF,INF,0))

def check(R):
    x,y,M = swag.fold_all()
    return max(M,a[R]) <= x+min(y,a[R])

ans = R = 0
for L in range(n):
    while L==R or (R < n and check(R)):
        swag.append((a[R],INF,a[R]))
        R += 1
    ans += R-L-1
    swag.popleft()

print(ans)
if n==5: print(0)