#include <iostream>
#include <algorithm>
#include <string>
using namespace std;
typedef struct node;	//这里
typedef node *tree;
struct node{
	tree lc,rc;
	char data;
};
tree bt;
int i;
string s;
void build(tree &bt) {
	if(s[++i]!='.') {
		bt=new node;
		bt->data=s[i];
		build(bt->lc);
		build(bt->rc);
	} else {
		bt=NULL;
	}
	return ;
}
void printmid(tree bt) {
	if(bt!=NULL) {
		printmid(bt->lc);
		cout<<bt->data;
		printmid(bt->rc);
	}
	return ;
}
void printaft(tree bt) {
	if(bt!=NULL) {
		printaft(bt->lc);
		printaft(bt->rc);
		cout<<bt->data;
	}
}
int main() {
	cin>>s;
	i=-1;
	build(bt);
	printmid(bt);
	cout<<endl;
	printaft(bt);
	cout<<endl;
	return 0;
}

不知道为啥，一直有一条warning: 'typedef' was ignored in this declaration。请大佬们把警告去掉