import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        // 入力受付
        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();
        String s = scan.next();
        char array[] = s.toCharArray();

        for (int i = 0; i < n; i++) {
            if (array[i] != '0') {
                for (int j = i + 1; j < n; j++) {
                    if (array[i] == array[j]) {
                        array[j] = '0';
                    } else {
                        break;
                    }
                }
            }

        }

        String result = String.valueOf(array);
        result = result.replaceAll("0", "");

        System.out.println(result.length());

    }

}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz