def main():
    import sys
    input = sys.stdin.read
    data = input().split()
    N = int(data[0])
    A = list(map(int, data[1:N+1]))
    count = 0

    for i in range(N):
        for j in range(i + 1, N):
            # Perform the swap
            A[i], A[j] = A[j], A[i]
            valid = True
            # Check affected triplets for i
            for k in [i-2, i-1, i]:
                if k < 0:
                    continue
                if k + 2 >= N:
                    break
                x, y, z = A[k], A[k+1], A[k+2]
                if y != max(x, y, z) and y != min(x, y, z):
                    valid = False
                    break
            if not valid:
                A[i], A[j] = A[j], A[i]
                continue
            # Check affected triplets for j
            for k in [j-2, j-1, j]:
                if k < 0:
                    continue
                if k + 2 >= N:
                    break
                x, y, z = A[k], A[k+1], A[k+2]
                if y != max(x, y, z) and y != min(x, y, z):
                    valid = False
                    break
            if valid:
                count += 1
            # Undo the swap
            A[i], A[j] = A[j], A[i]
    print(count)

if __name__ == "__main__":
    main()