Minimum Stone Removals to Avoid Adjacent Duplicates

You are given a row of n stones, each with a color represented by a character. Your task is to calculate the minimum number of stones to remove so that no two adjacent stones have the same color.

More formally, given a string stones of length n, you need to remove stones such that for every valid index i (1 ≤ i < n), the condition \[ s_i \neq s_{i+1} \] holds true. If there are consecutive stones with the same color, you must remove all but one from each group.

Example: For n = 3 and stones = "RRG", you can remove one of the adjacent 'R's to obtain "RG", which satisfies the condition. Thus, the answer is 1.

inputFormat

The input consists of two lines:

1. The first line contains a single integer \( n \) (1 ≤ n ≤ 100), representing the number of stones.
2. The second line contains a string of length \( n \) where each character denotes a color of a stone.

You should read input from stdin.

outputFormat

Output a single integer representing the minimum number of stones that need to be removed so that no two adjacent stones have the same color. Print the result to stdout.

## sample

3
RRG

1

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