import java.io.*;
import java.util.*;
import java.util.regex.Pattern;
import java.util.regex.Matcher;
public class Solution {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        Pattern pattern = Pattern.compile("(.)(?!\\1)"); 
        // "\\1" is a backreference to the first captured group. It is a backreference which will be translated into the same character found in (.), whatever character that is.
        // Note: Does not work without parenthesis: ".(?!\\1)"
        Matcher matcher = pattern.matcher(scanner.next());
        int count=0;
        while(matcher.find()) count++;
        System.out.println("Number of matches : "+count);
    }
}

r"(.)(?!\1)"