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#include <iostream>

using namespace std;

int main()
{
	int n, t;
	
	cin >> n;
	
	cin >> t;
		
	bool k = 0;
	int ost = t;
	int a = 0;
	
	bool p = 1;
	int ost2 = t;
	int b = 0;
	
	for(int i = 2; i <= n; ++i)
	{
		cin >> t;
		if(!k)
		{
			if(t >= ost)
			{
				++a;
				ost = -1e9;
			}
			else ost = t;
		}
		else
		{
			if(t <= ost)
			{
				++a;
				ost = 1e9;
			}
			else ost = t;
		}
		
		k ^= 1;
	
		if(!p)
		{
			if(t >= ost2)
			{
				++b;
				ost2 = -1e9;
			}
			else ost2 = t;
		}
		else
		{
			if(t <= ost2)
			{
				++b;
				ost2 = 1e9;
			}
			else ost2 = t;
		}
		
		p ^= 1;
	}
	
	cout << min(a, b);
	return 0;
}