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

程式分析：等價於計算 相鄰兩個字元是相同的 的個數

AC通過程式碼：

#include<stdio.h>

int main()
{
    int i;
    int n,sum=0;
    scanf("%d",&n);
    if(n<1 || n>50) return 0;
    char s[51]={0};
    scanf("%s",s);
    for(i=0;i<n;i++)
    {
    	if(s[i]==s[i+1])
    	{
    		sum++;
	}
    }
    printf("%d\n",sum);
    return 0;
}