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def check(xs, up=False):
    prev_x = -10**9 if up else 10**9
    changes = 0
    for x in xs:
        if up and prev_x >= x:
            changes += 1
            prev_x = 10**9
        elif not up and prev_x <= x:
            changes += 1
            prev_x = -10**9
        else:
            prev_x = x
        up = not up
    return changes

n = int(input())
xs = list(map(int, input().split()))

c1 = check(xs, True)
c2 = check(xs, False)
print(min(c1, c2))