#include <stdio.h>

int main(void)
{
	int n;
	int a[100];
	int total = 0;
	int max, min;
	int i, j;

	scanf("%d", &n);
	for (i = 0; i < n; i++) 
		scanf("%d", &a[i]);

	for (i = 0; i < n - 2; i++) {
		max = 1;
		min = 100;
		if (a[i] != a[i + 1] && a[i] != a[i + 2] && a[i + 1] != a[i + 2]) {
			for (j = i; j < i + 3; j++) {
				if (max < a[j])
					max = a[j];
				if (min > a[j])
					min = a[j];
			}
			if (a[i + 1] == max || a[i + 1] == min)
				total++;
		}
	}

	printf("%d\n", total);

	return 0;
}