#include <iostream>

#include <string>

#include <vector>

#include <queue>

using namespace std;

struct treeNode{

    int val;

    treeNode *left;

    treeNode *right;

    treeNode(){}

    treeNode(int x):

        val(x),left(NULL),right(NULL){}

};

int s_to_i(string str){

    int v=;

    unsigned int i=;

    while(i<str.size()){

        v=v*+str[i]-'';

    }

    return v;

}

treeNode* buildTree(int N){

    if(N==){

        return NULL;

    }

    int i=;

    int v=;

    char c;

    cin>>c;

    if(c=='#') return NULL;

    v=c-'';

    queue<treeNode*> q;

    treeNode *root=new treeNode(v);

    q.push(root);

    while(i<N&&!q.empty()){

        treeNode *node=q.front();

        q.pop();

        if(i<N){

            cin>>c;i++;

            if(c!='#'){

                v=c-'';

                treeNode *lchild=new treeNode(v);

                node->left=lchild;

                q.push(lchild);

            }

        }

        if(i<N){

            cin>>c;i++;

            if(c!='#'){

                v=c-'';

                treeNode *rchild=new treeNode(v);

                node->right=rchild;

                q.push(rchild);

            }

        }

    }

    return root;

}

void serialize(treeNode *root){

    if(root==NULL){

        cout<<'#'<<endl;return;

    }

    cout<<root->val<<endl;

    if(root->left!=NULL || root->right!=NULL)

        serialize(root->left);

    if(root->left!=NULL || root->right!=NULL)

        serialize(root->right);

}

int main()

{

    int N;

    cin>>N;

    cout << "Build Tree" << endl;

    treeNode *root=buildTree(N);

    cout << "serialize Tree" <<endl;

    serialize(root);

    return ;

}