import java.io.*;
import java.util.Arrays;

class Main {
    static InputStreamReader isr = new InputStreamReader(System.in);
    static BufferedReader in = new BufferedReader(isr);
    static OutputStreamWriter osw = new OutputStreamWriter(System.out);
    static BufferedWriter out = new BufferedWriter(osw);

    static char non = '-';
    static int n, root;
    static int[] lc = new int[11];
    static int[] rc = new int[11];
    static int[] p = new int[11];
    static {
        Arrays.fill(lc, -1);
        Arrays.fill(rc, -1);
        Arrays.fill(p, -1);
    }

    static void levelOrder() throws IOException {
        int[] queue = new int[11];
        int head = 0, tail = 0;
        queue[tail++] = root;
        while (tail > head) {
            int e = queue[head++];
            out.write(String.format("%d ",e));
            if (lc[e] != -1) queue[tail++] = lc[e];
            if (rc[e] != -1) queue[tail++] = rc[e];
        }
    }

    static void inOrder(int e) throws IOException {
        if (lc[e] != -1) inOrder(lc[e]);
        out.write(String.format("%d ",e));
        if (rc[e] != -1) inOrder(rc[e]);
    }

    public static void main(String[] args) throws IOException {

        n = Integer.parseInt(in.readLine());
        String[] strs;
        for (int i = 0; i < n; i++) {
            strs = in.readLine().split(" ");
            int l = (strs[0].charAt(0) == non) ? -1 : Integer.parseInt(strs[0]);
            int r = (strs[1].charAt(0) == non) ? -1 : Integer.parseInt(strs[1]);
            lc[i] = l;
            rc[i] = r;
            if (l != -1) p[l] = i;
            if (r != -1) p[r] = i;
        }
        //翻转
        for (int i = 0; i < n; i++) {
            int temp = lc[i];
            lc[i] = rc[i];
            rc[i] = temp;
        }
        //找根节点
        for (int i = 0; i < n; i++) {
            if (p[i] == -1) {
                root = i;
                break;
            }
        }

        levelOrder();
        out.write('\n');
        inOrder(root);

        in.close();
        isr.close();
        out.flush();
        out.close();
        osw.close();
    }
}