#include <iostream>
using namespace std;
 
 
  char ss[]={'a', 'b', 'c'};
   char sss[16];
   int N=sizeof(ss)/sizeof(ss[-1]);
 
   void pa(int u){
      sss[u]=0;
      int n=1;
      for (int i=0;i<u;i++)
         n*=N;
      for (int y=0;y<n;y++){
         int j=y;
      for (int o=u-1;o>=0;o--){
         sss[o]=ss[j%N];
         j/=N;
      }
      printf("%s\n",sss);
      }
 
   }
 
   void ma(){
      for (int n=1;n<=N;n++)
        pa(n);
   }
 
 
int main() {
	ma();
	// your code goes here
	return 0;
}

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