n=int(input())
a=list(map(int,input().split()))
if n==1:
  print(1)
  exit(0)

from itertools import groupby
gr=groupby(a)
l=[]
for k,g in gr:
  l.append(len(list(g)))
ans=0
t=0
m=[]

if len(l)==1:
  print(l[0])
  exit(0)

for i in range(len(l)):
  if l[i]>1:
    ans+=l[i]
    m.append(t)
    t=0
  else:
    if i>0 and l[i-1]>1:continue
    if i<n-1 and l[i+1]>1:continue
    t+=1
if t!=0:
  m.append(t)
for mm in m:
  ans+=(mm+2-1)//2
print(ans)