题解 | #合唱队#

def max_len(ls):
    dp = [1] * len(ls)  # 存放每个位置左边符合要求的子序列长度
    for i in range(len(ls)):
        for j in range(i):
            if ls[i] > ls[j] and dp[i] < dp[j] + 1:
                dp[i] = dp[j] + 1
    return dp  # 1, 1, 1, 2, 2, 1, 3, 4


N = int(input())
ls = list(map(int, input().split()))
left = max_len(ls)
right = max_len(ls[::-1])[::-1]


max_length = 0
for i in range(N):
    if left[i] + right[i] - 1 > max_length:
        max_length = left[i] + right[i] - 1

print(N - max_length)