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#2572. 装箱问题

Estadísticas

一个有序整数对 $(x, y)$ 被称为一个盒子。一个盒子序列 $(c_1, d_1), (c_2, d_2), \dots, (c_m, d_m)$ 如果满足以下不等式,则被称为一个链: $$c_1 \le c_2 \le \dots \le c_m, \quad d_1 \le d_2 \le \dots \le d_m$$

给定 $n$ 个盒子:$(a_1, b_1), (a_2, b_2), \dots, (a_n, b_n)$。请找出你可以从中选择并划分为不超过 $k$ 条链的最大盒子数量。你可以重新排列这些盒子以组成链。

输入格式

第一行包含两个整数 $n$ 和 $k$ ($1 \le n \le 10^5, 1 \le k \le 100$)。 接下来的 $n$ 行中,第 $i$ 行包含两个整数 $a_i$ 和 $b_i$ ($1 \le a_i, b_i \le 10^9$)。

输出格式

输出一个整数:答案。

样例

输入 1

4 1
2 2
4 2
3 4
5 5

输出 1

3

输入 2

4 2
2 2
4 2
3 4
5 5

输出 2

4

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