public static void main ( String [ ] args ) throws IOException {
  BufferedReader br = new BufferedReader ( new InputStreamReader ( System . in ) ) ;
  StringBuilder sb = new StringBuilder ( ) ;
  int n = Integer . parseInt ( br . readLine ( ) ) ;
  int [ ] teammates = new int [ 2 * n + 1 ] ;
  int [ ] [ ] strength = new int [ 2 * n + 1 ] [ 2 * n + 1 ] ;
  for ( int i = 2 ;
  i <= 2 * n ;
  i ++ ) {
    StringTokenizer st = new StringTokenizer ( br . readLine ( ) ) ;
    for ( int j = 1 ;
    j < i ;
    j ++ ) {
      strength [ i ] [ j ] = Integer . parseInt ( st . nextToken ( ) ) ;
    }
  }
  for ( int t = 0 ;
  t < n ;
  t ++ ) {
    int max = 0 ;
    int [ ] maxIdx = new int [ 2 ] ;
    for ( int i = 2 ;
    i <= 2 * n ;
    i ++ ) {
      for ( int j = 1 ;
      j < i ;
      j ++ ) {
        if ( teammates [ i ] != 0 || teammates [ j ] != 0 ) continue ;
        if ( strength [ i ] [ j ] > max ) {
          maxIdx [ 0 ] = i ;
          maxIdx [ 1 ] = j ;
          max = strength [ i ] [ j ] ;
        }
      }
    }
    teammates [ maxIdx [ 0 ] ] = maxIdx [ 1 ] ;
    teammates [ maxIdx [ 1 ] ] = maxIdx [ 0 ] ;
  }
  for ( int i = 1 ;
  i <= 2 * n ;
  i ++ ) sb . append ( teammates [ i ] ) . append ( " " ) ;
  System . out . println ( sb ) ;
}

public static void main ( String [ ] args ) throws IOException { BufferedReader br = new BufferedReader ( new InputStreamReader ( System . in ) ) ; StringBuilder sb = new StringBuilder ( ) ; int n = Integer . parseInt ( br . readLine ( ) ) ; int [ ] teammates = new int [ 2 * n + 1 ] ; int [ ] [ ] strength = new int [ 2 * n + 1 ] [ 2 * n + 1 ] ; for ( int i = 2 ; i <= 2 * n ; i ++ ) { StringTokenizer st = new StringTokenizer ( br . readLine ( ) ) ; for ( int j = 1 ; j < i ; j ++ ) { strength [ i ] [ j ] = Integer . parseInt ( st . nextToken ( ) ) ; } } for ( int t = 0 ; t < n ; t ++ ) { int max = 0 ; int [ ] maxIdx = new int [ 2 ] ; for ( int i = 2 ; i <= 2 * n ; i ++ ) { for ( int j = 1 ; j < i ; j ++ ) { if ( teammates [ i ] != 0 || teammates [ j ] != 0 ) continue ; if ( strength [ i ] [ j ] > max ) { maxIdx [ 0 ] = i ; maxIdx [ 1 ] = j ; max = strength [ i ] [ j ] ; } } } teammates [ maxIdx [ 0 ] ] = maxIdx [ 1 ] ; teammates [ maxIdx [ 1 ] ] = maxIdx [ 0 ] ; } for ( int i = 1 ; i <= 2 * n ; i ++ ) sb . append ( teammates [ i ] ) . append ( " ▁ " ) ; System . out . println ( sb ) ; }
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