N = int(input())
A = input().replace(' ', '')

all = N * (N + 1) // 2

def search_one():
    a = 0
    b = len(A)
    while True:
        j = a + (b - a) // 2
        if '1' * j in A:
            a = j
        else:
            b = j
        if b - a < 5:
            break
    return b

i = N

onecnt = 0
while i > 0:
    i = search_one()
    found = False
    while found == False and i > 0:
        o = A.count('1' * i)
        if o > 0:
            onecnt += (i * (i + 1) // 2) * o
            A = A.replace('1' * i, '')
            found = True
        else:
            i -= 1
    
print(all - onecnt)