// editor5
import java.util.*;
class Node {
    int data;
    Node left, right;
    Node(int data) {
        this.data = data;
        left = right = null;
    }
}
public class main {
    static Node insert(Node root, int value) {
        if (root == null) {
            return new Node(value);
        }
        if (value < root.data) {
            root.left = insert(root.left, value);
        } else {
            root.right = insert(root.right, value);
        }
        return root;
    }
    static void inorder(Node root, List<Integer> result) {
        if (root == null) return;
        inorder(root.left, result);
        result.add(root.data);
        inorder(root.right, result);
    }
    public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
        try {
            int n = sc.nextInt();
            if (n < 0) {
                System.out.print("Invalid input");
                return;
            }
            Node root = null;
            for (int i = 0; i < n; i++) {
                int value = sc.nextInt();
                if (value < 0) {
                    System.out.print("Invalid input");
                return;
                }
                root = insert(root, value);
            }
            List<Integer> result = new ArrayList<>();
            inorder(root, result);
            StringBuilder sb = new StringBuilder<>();
            
            for (int i = 0; i < result.size(); i++) {
                sb.append(result.get(i));
                if (i < reslut.size() - 1) sb.append(" ");
            }
            System.out.print(sb.toString());
        } catch (Exception e) {
            System.out.print("Invalid input");
        }
    }
}