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`

#include<bits/stdc++.h>
using namespace std;
int n;
vector<char> path;
bool used[30];
void dfs(int Min)
{
	cout<<"(";
	for(int i=0;i<path.size();i++)
	{
		cout<<path[i];
	}
	cout<<")";
	cout<<endl;
	for(int i=Min;i<n;i++)
	{
		path.push_back((char)('a'+i));
		dfs(i+1);
		path.pop_back();
	}
	return ;
}
int main()
{
	cin>>n;
	dfs(0);
	return 0;
}`