import java.util.Scanner; public class FiveKeyboard { public static void main(String[] args) { Scanner sc = new Scanner(System.in); // 1 1 1 String screen = ""; // 屏幕上的英文 String selected = ""; // 所选的英文 String paste = ""; // 剪切板的英文 while (sc.hasNext()) { int l = sc.nextInt(); if (l == 1) { // a if (selected.length() == 0) { screen = screen.concat("a"); } else { screen = screen.replace(selected, "a"); selected = ""; } } else if (l == 2) { // ctrl-c if (selected.length() > 0) { paste = selected; } } else if (l == 3) { // ctrl-x if (selected.length() > 0) { paste = selected; screen = screen.replace(selected, ""); selected = ""; } } else if (l == 4) { // ctrl-v if (paste.length() == 0){ continue; } if (selected.length() > 0) { screen = screen.replace(selected, paste); selected = ""; } else { screen = screen.concat(paste); } } else if (l == 5) { // ctrl-a if (screen.length() > 0){ selected = screen; } } } System.out.print(screen.length()); } }