CF605A.Sorting Railway Cars

An infinitely long railway has a train consisting of n cars, numbered from 1 to n (the numbers of all the cars are distinct) and positioned in arbitrary order. David Blaine wants to sort the railway cars in the order of increasing numbers. In one move he can make one of the cars disappear from its place and teleport it either to the beginning of the train, or to the end of the train, at his desire. What is the minimum number of actions David Blaine needs to perform in order to sort the train?

一条无限长的铁路线上有一列由 $n$ 节车厢组成的列车，车厢编号为 $1$ 到 $n$（所有车厢编号互不相同），且初始时按任意顺序排列。大卫·布莱恩希望将列车按编号升序排序。在一次操作中，他可以任选一节车厢，使其从当前位置消失，并根据自己的意愿将其瞬移到列车最前端或最末端。问：大卫·布莱恩至少需要执行多少次操作才能将列车排好序？

The first line of the input contains integer n (1 ≤ n ≤ 100 000) — the number of cars in the train.

The second line contains n integers p__i (1 ≤ p__i ≤ n, p__i ≠ p__j if i ≠ j) — the sequence of the numbers of the cars in the train.

输入的第一行包含一个整数 $n$（$1 ≤ n ≤ 100\,000$）——列车中车厢的数量。

第二行包含 $n$ 个整数 $p_i$（$1 ≤ p_i ≤ n$，且当 $i ≠ j$ 时，$p_i ≠ p_j$）——列车中车厢编号的序列。

Print a single integer — the minimum number of actions needed to sort the railway cars.

输出一个整数——对火车车厢进行排序所需的最少操作次数。

In the first sample you need first to teleport the 4-th car, and then the 5-th car to the end of the train.

在第一个样例中，你需要先将第 4 辆车传送至列车末尾，再将第 5 辆车传送至列车末尾。