#include<iostream.h>

typedef char TElemtype;

typedef struct Btree

{

    TElemtype data;

    struct Btree *Lchild,*Rchild;

}BTnode,*btree;

void create_btree(btree &root)

{

    int i,j;

    btree s,p[];

    cin>>i;

    while(i!=)

    {

        s=new BTnode;

        cin>>s->data;

        s->Lchild=s->Rchild=NULL;

        p[i]=s;

        if(i==)

            root=s;

        else

        {

            j=i/;

            if(i%==)

                p[j]->Lchild=s;

            else

                p[j]->Rchild=s;

        }

        cin>>i;

    }

}

void create_btree2(btree &root,char str[])   

{

    char ch;

    static int i=;

    ch=str[i++];

    if(ch=='.')

    {

        root=NULL;

    }

    else

    {

        root=new BTnode;

        root->data=ch;

        create_btree2(root->Lchild,str);

        create_btree2(root->Rchild,str);

    }

}

void preorder(btree root)

{

    if(root)

    {

        cout<<root->data;

        preorder(root->Lchild);

        preorder(root->Rchild);

    }

}

void inorder(btree root)

{

    if(root)

    {

        inorder(root->Lchild);

        cout<<root->data;

        inorder(root->Lchild);

    }

}

void postorder(btree root)

{

    if(root)

    {

        postorder(root->Lchild);

        postorder(root->Lchild);

        cout<<root->data;

    }

}

void main()

{

    btree root;

    //create_btree(root);

    char str[];

    cin>>str;

    create_btree2(root,str);

    preorder(root);

}