from itertools import groupby

n, *a = map(int, open(0).read().split())
g = [len(list(g)) for k, g in groupby(a)]
ans = 0
flg = 1
for x in g:
	if flg:
		ans += x
		flg = 0
	else:
		ans += x - 1
		if x == 1:
			flg = 1
print(ans)