import std.algorithm, std.container, std.conv, std.math, std.range, std.typecons, std.stdio, std.string;

auto rdsp(){return readln.splitter;}
void pick(R,T)(ref R r,ref T t){t=r.front.to!T;r.popFront;}
void readV(T...)(ref T t){auto r=rdsp;foreach(ref v;t)pick(r,v);}

void main()
{
  int n; readV(n);

  foreach (i; 0..n) {
    write("a");
    foreach (j; 0..5) write(cast(char)(i/10^^j%10+'a'));
    write("a");
    if (i == n-1) write("n");
    writeln;
  }
}