Stones on the Table

Time Limit: 1000 ms Memory Limit: 65536 KiB

Problem Description

      There are n stones on the table in a row, each of them can be red, green or blue. Count the minimum number of stones to take from the table so that any two neighboring stones had different colors. Stones in a row are considered neighboring if there are no other stones between them.

Input

 There are multiple test cases.
For each test case:
The first line contains integer n (1 ≤ n ≤ 50) — the number of stones on the table.
The next line contains string s, which represents the colors of the stones. We'll consider the stones in the row numbered from 1 to n from left to right. Then the i-th character s equals "R", if the i-th stone is red, "G", if it's green and "B", if it's blue.

Output

 For each test case:
Print a single integer — the answer to the problem.

Sample Input

3
RRG

Sample Output

1

Hint

 

Source

qinchuan