Template Library Management

As an experienced ACMer, you must have known the importance of "code template library". With the help of pre-printed code library, you can implement the complicated algorithms correctly and efficiently. However, the size of the library is strictly limited during the contest. For example, you can only take at most 25 pages of printed codes in World Finals. So you must choose carefully which code template should be included.
Now your team is participating a programming contest whose rules are slightly different from ICPC. This contest consists of N problems, and you must solved them in order: Before you solve the (i+1)^th problem, you must solve the i^th problem at first. And solving the i^th problem requires a specified code template T_i.
You are allowed to hold M code templates only. At the beginning of the contest, your are holding templates numbered 1, 2, ..., M. During the contest, if the problem you are trying to solve requires code template T_i, and T_i is happened at your hand (i.e, one of the M code templates you are holding is T_i), you can solve it immediately. On the other hand, if you are not holding T_i, you must call your friends who are outside the arena for help (yes, it is permitted, not cheating). They can give you the code template you need. Because you are only allowed to hold M code templates, after solving current problem, you must choose to drop the code you get from your friends just now, or to keep it and drop one of the M templates at your hand previously.
Given the problem sequence in the contest and the limitation M, you want finish all the problems with minimum number of calling your friends.

The first line of each test case contains two numbers N (1 <= N <= 100000) and M (1 <= M <= 100000). The second line contains N numbers T₁, T₂, ..., T_N (1 <= T_i <= 10⁹), indicating the code templates required by each problem.

Output one line for each test case, indicating the minimum number of calling friends for help.

4 3
1 2 3 4
11 3
4 1 2 1 5 3 4 4 1 2 3

1
4

RoBa

2012 Multi-University Training Contest 10