Minimum Items After Merge

Given a sequence of n items, you are allowed to merge consecutive items if they are identical. Merging a group of adjacent identical items results in a single item representing that group. Determine the minimum number of items remaining after performing all possible merge operations.

Formally, if the input sequence is \(a_1, a_2, \ldots, a_n\), then after merging, the number of items left is equal to the number of contiguous blocks of identical items.

Example: For the sequence [2, 2, 3, 3, 1, 1, 1], there are three contiguous blocks: [2,2], [3,3] and [1,1,1]. Hence, the answer is 3.

inputFormat

The input is given from stdin in the following format:

• The first line contains an integer n representing the number of items.
• If n > 0, the second line contains n space-separated integers representing the items.

If n is 0, the second line is omitted.

outputFormat

Print a single integer to stdout representing the minimum number of items remaining after performing all merge operations.

## sample

7
2 2 3 3 1 1 1

3

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