public static void main ( String args [ ] ) throws Exception {
  Scanner sc = new Scanner ( System . in ) ;
  int N = sc . nextInt ( ) ;
  int K = sc . nextInt ( ) ;
  long [ ] x = new long [ N ] ;
  long [ ] y = new long [ N ] ;
  for ( int i = 0 ;
  i < N ;
  i ++ ) {
    x [ i ] = sc . nextLong ( ) ;
    y [ i ] = sc . nextLong ( ) ;
  }
  long ans = 2000000000 ;
  ans *= ans ;
  for ( int i = 0 ;
  i < N ;
  i ++ ) {
    long x1 = x [ i ] ;
    for ( int j = 0 ;
    j < N ;
    j ++ ) {
      long x2 = x [ j ] ;
      for ( int k = 0 ;
      k < N ;
      k ++ ) {
        long y1 = y [ k ] ;
        for ( int l = 0 ;
        l < N ;
        l ++ ) {
          long y2 = y [ l ] ;
          if ( x1 < x2 && y1 < y2 ) {
            int num = 0 ;
            for ( int m = 0 ;
            m < N ;
            m ++ ) {
              if ( x1 <= x [ m ] && x [ m ] <= x2 && y1 <= y [ m ] && y [ m ] <= y2 ) {
                num ++ ;
              }
              if ( num >= K ) {
                ans = Math . min ( ans , ( x2 - x1 ) * ( y2 - y1 ) ) ;
              }
            }
          }
        }
      }
    }
  }
  System . out . println ( ans ) ;
}

public static void main ( String args [ ] ) throws Exception { Scanner sc = new Scanner ( System . in ) ; int N = sc . nextInt ( ) ; int K = sc . nextInt ( ) ; long [ ] x = new long [ N ] ; long [ ] y = new long [ N ] ; for ( int i = 0 ; i < N ; i ++ ) { x [ i ] = sc . nextLong ( ) ; y [ i ] = sc . nextLong ( ) ; } long ans = 2000000000 ; ans *= ans ; for ( int i = 0 ; i < N ; i ++ ) { long x1 = x [ i ] ; for ( int j = 0 ; j < N ; j ++ ) { long x2 = x [ j ] ; for ( int k = 0 ; k < N ; k ++ ) { long y1 = y [ k ] ; for ( int l = 0 ; l < N ; l ++ ) { long y2 = y [ l ] ; if ( x1 < x2 && y1 < y2 ) { int num = 0 ; for ( int m = 0 ; m < N ; m ++ ) { if ( x1 <= x [ m ] && x [ m ] <= x2 && y1 <= y [ m ] && y [ m ] <= y2 ) { num ++ ; } if ( num >= K ) { ans = Math . min ( ans , ( x2 - x1 ) * ( y2 - y1 ) ) ; } } } } } } } System . out . println ( ans ) ; }
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(variable_declarator name: (identifier) value: (array_creation_expression type: (integral_type) dimensions: (dimensions_expr (identifier))))) (local_variable_declaration type: (array_type element: (integral_type) dimensions: (dimensions)) declarator: (variable_declarator name: (identifier) value: (array_creation_expression type: (integral_type) dimensions: (dimensions_expr (identifier))))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (block (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (expression_statement (assignment_expression left: (identifier) right: (identifier))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (array_access array: (identifier) index: (identifier)))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (array_access array: (identifier) index: (identifier)))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (array_access array: (identifier) index: (identifier)))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (array_access array: (identifier) index: (identifier)))) (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (binary_expression left: (identifier) right: (identifier)))) consequence: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (binary_expression left: (binary_expression left: (identifier) right: (array_access array: (identifier) index: (identifier))) right: 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(identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))