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import io
import os
 
input=(io.BytesIO(os.read(0, os.fstat(0).st_size)).readline)

n = int(input())
a = list(map(int,input().split()))
def sgn(a):
	return -1 if a<0 else 1 if a>0 else 0
	
def calc(n,a,d):
	k = 0
	b = a[0]
	for i in range(1,n):
		r = sgn(a[i]-b)
		if r != d:
			k += 1
			b = 10000000*d
		else:
			b = a[i]
		d = -d
	return k
	
print(min(calc(n,a,1),calc(n,a,-1)))