#include <iostream>
#include <string>
#include <map>
using namespace std;
int main(int argc, char* argv[])
{
	int n;
	cin>>n;
	int m=20;
	char ch='a';
	int i,j;
	char ch1=ch;
	string S;
	map<string,int> myMap;
	map<string,int>::iterator mit;	
	for (i=0;i<n;i++){
		int index;
		for (j=0;j<m;j++){
			if (j==0){
				S.push_back(ch1);
				if (i==n-1){
					S.push_back('n');
					break;
				}
				continue;
			}
			index=(i+j)%26;
			if (ch+index>'z'){
				ch='a';
			}
			if (ch+index=='n'){
				index++;
			}
			S.push_back(char(ch+index));
			ch1=ch+index;
		}
		mit=myMap.find(S);
		if (mit==myMap.end()){
			myMap[S]=1;
		}else{
			while(true){
				S.erase(S.begin()+1);
				mit=myMap.find(S);
				if (mit==myMap.end()){
					myMap[S]=1;
					break;
				}
			}
		}
		cout<<S<<endl;
		S.clear();
	}
	return 0;
}