#include<bits/stdc++.h>
using namespace std;
//À¨ºÅ½á¹¹Ìå
struct kuohao{
	int id;
	char c;
};
stack<kuohao>s;//Õ»ÓÃÀ´ÅжÏ
vector<kuohao>tmp;//°ÑÕû¸ö´®´æÏÂÀ´
vector<kuohao>not_pipei;//´æûÓÐÆ¥ÅäµÄÀ¨ºÅ
//ÅжÏÊÇ·ñÔÚδƥÅäµ±ÖÐ
bool in(int x){
	for(int i = 0;i < (int)not_pipei.size();i++)
		if(not_pipei[i].id == x)
			return true;
	return false;
}
bool pipei(char ch){
	if((s.top().c == '(' && ch == ')') || (s.top().c == '[' && ch == ']') || (s.top().c == '{' && ch == '}'))
		return true;
	return false;
}
int main(){
	char ch_;
	int id = 1;
	//¶ÁÈë
	while(ch_ != '\n'){
		ch_ = getchar();
		tmp.push_back((kuohao){id,ch_});
		if(pipei(ch_))
			s.pop();
		else
			s.push((kuohao){id,ch_});
		id++;
	}
	//Èç¹ûÈ«²¿Æ¥Å䣬ֱ½ÓÊä³ö
	if(s.empty())
		for(int i = 0;i < (int)tmp.size();i++)
			putchar(tmp[i].c);
	else{
		//½«ËùÓÐδƥÅäµÄÀ¨ºÅ¼ÓÈëÊý×éÖÐ
		while(!s.empty()){
			not_pipei.push_back(s.top());
			s.pop();
		}
		//Êä³ö
		for(int i = 0;i < (int)tmp.size();i++){
			char ch = tmp[i].c;
			//Èç¹ûδƥÅ䣬½«ÆäÆ¥Åä
			if(in(i + 1)){
				if(ch == '(' || ch == ')')
					puts("()");
				else if(ch == '[' || ch == ']')
					puts("[]");
				else
					puts("{}");
			}
			else putchar(ch);
		}
	}
	return 0;
}