import java.util.Arrays;import java.util.Scanner;public class Main { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); int n = scanner.nextInt(); int[] prices = new int[n]; for (int i = 0; i < n; i++) { prices[i] = scanner.nextInt(); } Arrays.sort(prices); // 将商品价格从小到大排序 int totalCost = 0; int freeCount = 0; // 统计免费商品数量 for (int i = n - 1; i >= 0; i -= 3) { int p = prices[i]; // 买二赠一的两件商品中较便宜的价格 int cost = p; // 两件商品的总价格 if (i - 1 >= 0) { cost += prices[i - 1]; } totalCost += cost; freeCount++; // 获得一件免费商品 if (freeCount % 3 == 0) { i++; // 每三个商品中有一件是免费的，所以要跳过免费商品 } } System.out.println(totalCost); }}