#include<bits/stdc++.h>
using namespace std;
char zuo[101],you[101];
int top,sta[101];
int main(){
	string s;
	cin>>s;
	int len=s.length();
	for(int i=0;i<len;i++){
		if(s[i]=='('||s[i]=='['){
			zuo[++top]=s[i];
			sta[top]=i;
			if(s[i]=='(')you[i]=')';
			else you[i]=']';
		}
		if(s[i]==')'){
			if(top!=0&&zuo[top]=='('){
				you[sta[top]]=' ';
				top--;
			}
			else you[i]='(';
		}
		if(s[i]==']'){
			if(top!=0&&zuo[top]=='['){
				you[sta[top]]==' ';
				top--;
			}
			else you[i]='[';
		}
	}
	for(int i=0;i<len;i++){
		if(you[i]=='('||you[i]=='[')cout<<you[i]<<s[i];
		else if((you[i]==')'||you[i]==']'))cout<<s[i]<<you[i];
		else cout<<s[i];
	}
	return 0;
}

哪里错了感觉思路挺对的