Stones on the Table

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

问题简述

不同颜色石头排列（红，蓝，绿），要求拿出最少的石头，使相邻石头颜色不同。

程序分析

定义字符型数组，通过比较相邻元素的ASCLL码值，同时定义一变量h=0，若相邻两元素ASCLL值相同，则h+1，最后h值即为要拿出的最小值。

AC程序如下：

//CodeForces-266A
#include<iostream>
#include<string.h>
using namespace std;
int main()
{
    int n, i, j, h = 0;
    cin >> n;
    char a[50];
    cin >> a;
    j = strlen(a);
    for (i = 0; i < j-1; i++)
    {
        if (a[i] == a[i + 1])
            h++;
    }
    cout << h;
    return 0;
}