n = int(input())
a = [int(i) for i in input().split()]

now = 10**9
li = [0]*n

for i in range(n-1):
    if a[i] == a[i+1]:
        li[i] = 1
        li[i+1] = 1
    else:
        continue

idx = 0
for i in range(n):
    if idx+1 >= n:
        break
    if li[idx] == 0 and li[idx+1] == 0:
        li[idx] = 1
        idx += 2
    else:
        idx += 1

if li[n-2] == 0 and li[n-1] == 0:
    li[n-1] = 1

print(sum(li))