import bisect

n = int(input())
a = list(map(int, input().split()))
transformed = [x - 1 for x in a]
lis = []

for num in transformed:
    idx = bisect.bisect_left(lis, num)
    if idx == len(lis):
        lis.append(num)
    else:
        lis[idx] = num

print(n - len(lis))