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#F2571. Stones on the Table

    ID: 2577 传统题 2000ms 256MiB 尝试: 0 已通过: 0 难度: 1 上传者: 标签>模拟编程与模拟入门难度共享题库Codeforces英文题面题目来源题面语言

Stones on the Table

题目描述

A. Stones on the Table
time limit per test
2 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output

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

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

Print a single integer − the answer to the problem.

Examples
Input
3
RRG
Output
1
Input
5
RRRRR
Output
4
Input
4
BRBG
Output
0

题目来源：fps-www.educg.net-codeforce-1-2833.xml.zip；FPS 共享题包，题包内第 2219 题。保留原作者与原赛事署名。