public static void main ( String [ ] args ) {
  Scanner in = new Scanner ( System . in ) ;
  int N = in . nextInt ( ) ;
  int Q = in . nextInt ( ) ;
  Map < Character , List < String >> map = new HashMap < > ( ) ;
  for ( char c = 'a' ;
  c <= 'f' ;
  c ++ ) {
    map . put ( c , new ArrayList < > ( ) ) ;
  }
  for ( int q = 0 ;
  q < Q ;
  q ++ ) {
    String expansion = in . next ( ) ;
    String compression = in . next ( ) ;
    map . get ( compression . charAt ( 0 ) ) . add ( expansion ) ;
  }
  Set < String > set = new HashSet < > ( ) ;
  set . add ( "a" ) ;
  for ( int n = 2 ;
  n <= N ;
  n ++ ) {
    Set < String > newSet = new HashSet < > ( ) ;
    for ( String compression : set ) {
      char c = compression . charAt ( 0 ) ;
      for ( String expansion : map . get ( c ) ) {
        newSet . add ( expansion + compression . substring ( 1 ) ) ;
      }
    }
    set = newSet ;
  }
  System . out . println ( set . size ( ) ) ;
}

public static void main ( String [ ] args ) { Scanner in = new Scanner ( System . in ) ; int N = in . nextInt ( ) ; int Q = in . nextInt ( ) ; Map < Character , List < String > > map = new HashMap < > ( ) ; for ( char c = ' a ' ; c <= ' f ' ; c ++ ) { map . put ( c , new ArrayList < > ( ) ) ; } for ( int q = 0 ; q < Q ; q ++ ) { String expansion = in . next ( ) ; String compression = in . next ( ) ; map . get ( compression . charAt ( 0 ) ) . add ( expansion ) ; } Set < String > set = new HashSet < > ( ) ; set . add ( " a " ) ; for ( int n = 2 ; n <= N ; n ++ ) { Set < String > newSet = new HashSet < > ( ) ; for ( String compression : set ) { char c = compression . charAt ( 0 ) ; for ( String expansion : map . get ( c ) ) { newSet . add ( expansion + compression . substring ( 1 ) ) ; } } set = newSet ; } System . out . println ( set . size ( ) ) ; }
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