#include<iostream> #include<iomanip> #include<cstring> #include<cstdio> using namespace std; int n; bool a[26]; char begin='a'; void dfs(string s,int k){ cout<<s<<")"<<endl; for(int i=k;i<n;i++){ char c=i+begin; dfs(s+c,i+1); } } signed main(){ cin>>n; dfs("(",0); return 0; }