#include<cstdio>

#include<cstring>

#include<iostream>

#include<algorithm>

int n,cnt,deep,bns,root;

struct data{

    int ls,rs,val;

}tr[];

int max(int a,int b){

    if(a<b)    return b;

    else return a;

}

void insert(int& rt,int x){

    ++bns;

    if(!rt){ rt=++cnt;tr[rt].val=x;deep=max(deep,bns);return; }

    if(x>tr[rt].val)    insert(tr[rt].rs,x);

    else insert(tr[rt].ls,x);

    return;

}

void dfs(int rt){

    if(tr[rt].ls)    dfs(tr[rt].ls);

    if(tr[rt].rs)    dfs(tr[rt].rs);

    printf("%d\n",tr[rt].val);

}

int main(){

    scanf("%d",&n);

    for(int i=;i<=n;i++){

        bns=;int x;

        scanf("%d",&x);

        insert(root,x);

    }

    printf("deep=%d\n",deep);

    dfs(root);

}