1 #include<algorithm>
 2 #include<iostream>
 3 #include<cstdlib>
 4 #include<cstring>
 5 #include<cstdio>
 6 #include<vector>
 7 #include<map>
 8 #include<set>
 9 using std::cin;
10 using std::cout;
11 using std::endl;
12 using std::find;
13 using std::set;
14 using std::map;
15 using std::pair;
16 using std::vector;
17 using std::multiset;
18 using std::multimap;
19 #define sz(c) (int)(c).size()
20 #define all(c) (c).begin(), (c).end()
21 #define iter(c) decltype((c).begin())
22 #define cls(arr,val) memset(arr,val,sizeof(arr))
23 #define cpresent(c, e) (find(all(c), (e)) != (c).end())
24 #define rep(i, n) for (int i = 0; i < (int)(n); i++)
25 #define tr(c, i) for (iter(c) i = (c).begin(); i != (c).end(); ++i)
26 #define pb(e) push_back(e)
27 #define mp(a, b) make_pair(a, b)
28 const int Max_N = 100100;
29 typedef unsigned long long ull;
30 struct Node {
31     int v;
32     Node *ch[2];
33     inline void setc(int _v, Node *p) {
34         v = _v;
35         ch[0] = ch[1] = p;
36     }
37 };
38 struct BST {
39     Node *root, *null, *tail;
40     Node stack[Max_N];
41     inline void init() {
42         tail = &stack[0];
43         null = tail++;
44         null->setc(0, NULL);
45         root = null;
46     }
47     inline Node *newNode(int v) {
48         Node *p = tail++;
49         p->setc(v, null);
50         return p;
51     }
52     inline void insert(Node *&x, int v) {
53         if (x == null) { x = newNode(v); return; }
54         insert(x->ch[v > x->v], v);
55     }
56     inline void dfs(vector<int> &res, Node *x) {
57         if (x != null) {
58             res.pb(x->v);
59             dfs(res, x->ch[0]);
60             dfs(res, x->ch[1]);
61         }
62     }
63     inline void insert(int v) {
64         insert(root, v);
65     }
66     inline void go() {
67         vector<int> res;
68         dfs(res, root);
69         int n = sz(res);
70         rep(i, n) printf("%d%c", res[i], i < n - 1 ? ‘ ‘ : ‘\n‘);
71     }
72 }bst;
73 int main() {
74 #ifdef LOCAL
75     freopen("in.txt", "r", stdin);
76     freopen("out.txt", "w+", stdout);
77 #endif
78     int n, v;
79     while (~scanf("%d", &n)) {
80         bst.init();
81         rep(i, n) scanf("%d", &v), bst.insert(v);
82         bst.go();
83     }
84     return 0;
85 }