public static void main ( String [ ] args ) {
  Scanner scan = new Scanner ( System . in ) ;
  int n = scan . nextInt ( ) ;
  int k = scan . nextInt ( ) ;
  long INF = 1000000007 ;
  long ans = 1 ;
  for ( int i = k + 1 ;
  i < n + k ;
  i ++ ) {
    ans *= i ;
    ans %= INF ;
  }
  long div [ ] = new long [ 31 ] ;
  div [ 0 ] = 1 ;
  for ( int i = 1 ;
  i < n ;
  i ++ ) {
    div [ 0 ] *= i ;
    div [ 0 ] %= INF ;
  }
  int [ ] two = new int [ 31 ] ;
  two [ 0 ] = 1 ;
  for ( int i = 1 ;
  i < 31 ;
  i ++ ) {
    two [ i ] = two [ i - 1 ] * 2 ;
    div [ i ] = div [ i - 1 ] * div [ i - 1 ] ;
    div [ i ] %= INF ;
  }
  long mom = 1 ;
  for ( int i = 0 ;
  i < 31 ;
  i ++ ) {
    if ( ( two [ i ] & ( INF - 2 ) ) > 0 ) {
      mom *= div [ i ] ;
      mom %= INF ;
    }
  }
  ans *= mom ;
  ans %= INF ;
  System . out . println ( ans ) ;
}

public static void main ( String [ ] args ) { Scanner scan = new Scanner ( System . in ) ; int n = scan . nextInt ( ) ; int k = scan . nextInt ( ) ; long INF = 1000000007 ; long ans = 1 ; for ( int i = k + 1 ; i < n + k ; i ++ ) { ans *= i ; ans %= INF ; } long div [ ] = new long [ 31 ] ; div [ 0 ] = 1 ; for ( int i = 1 ; i < n ; i ++ ) { div [ 0 ] *= i ; div [ 0 ] %= INF ; } int [ ] two = new int [ 31 ] ; two [ 0 ] = 1 ; for ( int i = 1 ; i < 31 ; i ++ ) { two [ i ] = two [ i - 1 ] * 2 ; div [ i ] = div [ i - 1 ] * div [ i - 1 ] ; div [ i ] %= INF ; } long mom = 1 ; for ( int i = 0 ; i < 31 ; i ++ ) { if ( ( two [ i ] & ( INF - 2 ) ) > 0 ) { mom *= div [ i ] ; mom %= INF ; } } ans *= mom ; ans %= INF ; System . out . println ( ans ) ; }
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