public static void main ( String [ ] args ) {
  Scanner in = new Scanner ( System . in ) ;
  int n = in . nextInt ( ) ;
  int m = in . nextInt ( ) ;
  int arr [ ] = new int [ n ] ;
  int gen [ ] = new int [ 11 ] ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    arr [ i ] = in . nextInt ( ) ;
    gen [ arr [ i ] ] ++ ;
  }
  long ans = 0 ;
  for ( int i = 1 ;
  i <= m ;
  i ++ ) {
    for ( int k = 1 ;
    k <= m ;
    k ++ ) {
      if ( i != k ) {
        ans += ( long ) gen [ i ] * gen [ k ] ;
      }
    }
  }
  System . out . println ( ans / 2 ) ;
}

public static void main ( String [ ] args ) { Scanner in = new Scanner ( System . in ) ; int n = in . nextInt ( ) ; int m = in . nextInt ( ) ; int arr [ ] = new int [ n ] ; int gen [ ] = new int [ 11 ] ; for ( int i = 0 ; i < n ; i ++ ) { arr [ i ] = in . nextInt ( ) ; gen [ arr [ i ] ] ++ ; } long ans = 0 ; for ( int i = 1 ; i <= m ; i ++ ) { for ( int k = 1 ; k <= m ; k ++ ) { if ( i != k ) { ans += ( long ) gen [ i ] * gen [ k ] ; } } } System . out . println ( ans / 2 ) ; }
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