public static void main ( String [ ] args ) {
  Scanner sc = new Scanner ( System . in ) ;
  int n = sc . nextInt ( ) ;
  long mod = 1000000007 ;
  long [ ] dp = new long [ 2 * n + 2 ] ;
  dp [ 0 ] = 1 ;
  dp [ 1 ] = 1 ;
  long sum = 2 ;
  for ( int i = 2 ;
  i < dp . length ;
  i ++ ) {
    dp [ i ] = ( sum - dp [ i - 2 ] + mod ) % mod ;
    sum = ( sum + dp [ i ] ) % mod ;
  }
  long res = 0 ;
  for ( int i = 0 ;
  i < n - 1 ;
  i ++ ) {
    res = ( res + dp [ i ] * ( n - 1 ) % mod * ( n - 1 ) % mod ) % mod ;
  }
  res = ( res + dp [ n - 1 ] * ( n - 1 ) % mod ) % mod ;
  for ( int i = 0 ;
  i < n - 1 ;
  i ++ ) {
    long coef = i + 2 ;
    if ( i == n - 2 ) coef -- ;
    res = ( res + dp [ i ] * coef % mod ) % mod ;
  }
  res = ( res + dp [ n - 1 ] ) % mod ;
  System . out . println ( res ) ;
}

public static void main ( String [ ] args ) { Scanner sc = new Scanner ( System . in ) ; int n = sc . nextInt ( ) ; long mod = 1000000007 ; long [ ] dp = new long [ 2 * n + 2 ] ; dp [ 0 ] = 1 ; dp [ 1 ] = 1 ; long sum = 2 ; for ( int i = 2 ; i < dp . length ; i ++ ) { dp [ i ] = ( sum - dp [ i - 2 ] + mod ) % mod ; sum = ( sum + dp [ i ] ) % mod ; } long res = 0 ; for ( int i = 0 ; i < n - 1 ; i ++ ) { res = ( res + dp [ i ] * ( n - 1 ) % mod * ( n - 1 ) % mod ) % mod ; } res = ( res + dp [ n - 1 ] * ( n - 1 ) % mod ) % mod ; for ( int i = 0 ; i < n - 1 ; i ++ ) { long coef = i + 2 ; if ( i == n - 2 ) coef -- ; res = ( res + dp [ i ] * coef % mod ) % mod ; } res = ( res + dp [ n - 1 ] ) % mod ; System . out . println ( res ) ; }
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