#include<bits/stdc++.h>
using namespace std;
char x[5];
void combination(int pos,char letter)
{
     x[pos]=letter;
   // cout<<x[pos]<<endl;
    if(pos>=3)
    {
        for(int i=1;i<=3;i++)
            cout<<x[i]<<" ";
        cout<<endl;
        return;
    }
    combination(pos+1,'a');
        combination(pos+1,'b');
        combination(pos+1,'c');
}
int main()
{
    combination(0,'a');
    return 0;
}