#include<iostream>
#include<string>
#include<vector>
using namespace std;

string tmp;
vector<string> res;

void DFS(int left,int right) {
    if(right<left) return;
    if(right==0&&left==0) {res.push_back(tmp); return;}
    if(left>0){
        tmp.push_back('(');
        DFS(left-1,right);
        tmp.pop_back();
    }
    if(right>0){
        tmp.push_back(')');
        DFS(left,right-1);
        tmp.pop_back();
    }
    return;
}
vector<string> generateParenthesis(int n) {
    DFS(n,n);
}
int main(){
    generateParenthesis(2);
    getchar();
}