#include <iostream>
#include <string>

using namespace std;

class permuter
{ protected:
    int pos[27];
    int inuse[27];
    int N;
  public:
    int perm[27];
    permuter(int n);
    bool next(); };

permuter::permuter(int n)
{ N = n;
  for (int i = 0; i < N; i += 1)
  { pos[i] = 1;
    inuse[i] = 0; }
  pos[n] = 0; }

bool permuter::next()
{ int n = N;
  while (n > 0)
  { pos[n] += 1;
    if (pos[n] <= N + 1 - n)
      break;
    pos[n] = 1;
    n -= 1; }

  if (n == 0)
    return false;

  for (int i = 1; i <= N; i += 1)
    inuse[i] = 0;

  for (int i = 1; i <= N; i += 1)
  { int w = pos[i];
    for (int j = 1; j <= N; j += 1)
    { if (! inuse[j])
      { w -= 1;
        if (w == 0)
        { perm[i] = j;
          inuse[j] = 1; } } } }
  return true; }

int main(int argc, char * argv[])
{ if (argc != 2)
  { cerr << "Put the number of items on the command line\n";
    exit(1); }
  const int n = atol(argv[1]);
  if (n < 0 || n > 26)
  { cerr << "Number of items limited to range 0...26\n";
    exit(1); }
  const string vars = "-abcdefghijklmnopqrstuvwxyz";
  permuter P(n);
  while (P.next())
  { for (int i = 1; i <= n; i += 1)
      cout << " " << vars[P.perm[i]];
    cout << "\n"; } }