题解 | #交错序列#

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        sc.nextLine();
        int ret = 1;

        String line = sc.nextLine(), cur = "";
        for (String l : line.split(" ")) {
            if (cur.equals("")) {
                cur = l;
            } else {
                if (!l.equals(cur)) {
                    ret++;
                    cur = l;
                }
            }
        }
        System.out.println(ret);
    }
}