#include<bits/stdc++.h>
using namespace std;

stack<int> stk;
bool vis[105];
int main(){
	memset(vis,0,sizeof(vis));
	string s;
	cin>>s;
	for(int i=0;i<s.size();i++){
		if(s[i]=='('||s[i]=='['||s[i]=='{'){
			stk.push(i);
		}else{
			int xx=stk.top();
			if(stk.empty()||s[i]!=s[xx]){
				vis[i]=1;
			}else{
				 stk.pop();
			}
		}
	}
	while(!stk.empty()){
		int xx=stk.top();
		vis[xx]=1;
		stk.pop();
	}
	for(int i=0;i<s.size();i++){
		if(!vis[i]) printf("%c",s[i]);
		else{
			if(s[i]=='('||s[i]==')') printf("()");
			if(s[i]=='['||s[i]==']') printf("[]");
			if(s[i]=='{'||s[i]=='}') printf("{}");
		}
	}
}