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

# Process the array to remove consecutive duplicates
processed = []
prev = None
for num in a:
    if num != prev:
        processed.append(num)
        prev = num

m = len(processed)
if m < 3:
    print(0)
else:
    up = 1
    down = 1
    for i in range(1, m):
        current = processed[i]
        prev_num = processed[i-1]
        if current > prev_num:
            new_up = down + 1
            new_down = down
        elif current < prev_num:
            new_down = up + 1
            new_up = up
        else:
            # This case is handled by preprocessing, so it's redundant here
            continue
        up, down = new_up, new_down
    max_len = max(up, down)
    print(max_len if max_len >= 3 else 0)