public static void main ( String [ ] args ) {
  Scanner sc = new Scanner ( System . in ) ;
  int t = sc . nextInt ( ) ;
  while ( t -- > 0 ) {
    int n = sc . nextInt ( ) ;
    char [ ] arr = new char [ 51 ] ;
    for ( int i = 0 ;
    i < 51 ;
    i ++ ) arr [ i ] = 'a' ;
    System . out . println ( new String ( arr ) ) ;
    for ( int i = 0 ;
    i < n ;
    i ++ ) {
      int x = sc . nextInt ( ) ;
      arr [ x ] = ( arr [ x ] == 'a' ) ? 'b' : 'a' ;
      System . out . println ( new String ( arr ) ) ;
    }
  }
}

public static void main ( String [ ] args ) { Scanner sc = new Scanner ( System . in ) ; int t = sc . nextInt ( ) ; while ( t -- > 0 ) { int n = sc . nextInt ( ) ; char [ ] arr = new char [ 51 ] ; for ( int i = 0 ; i < 51 ; i ++ ) arr [ i ] = ' a ' ; System . out . println ( new String ( arr ) ) ; for ( int i = 0 ; i < n ; i ++ ) { int x = sc . nextInt ( ) ; arr [ x ] = ( arr [ x ] == ' a ' ) ? ' b ' : ' a ' ; System . out . println ( new String ( arr ) ) ; } } }
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