public static void main ( String [ ] args ) throws IOException {
  BufferedReader bf = new BufferedReader ( new InputStreamReader ( System . in ) ) ;
  String [ ] str = bf . readLine ( ) . split ( " " ) ;
  int N = Integer . parseInt ( str [ 0 ] ) , K = Integer . parseInt ( str [ 1 ] ) ;
  int [ ] h = new int [ N ] ;
  for ( int i = 0 ;
  i < N ;
  i ++ ) {
    h [ i ] = Integer . parseInt ( bf . readLine ( ) ) ;
  }
  Arrays . sort ( h ) ;
  int min = h [ N - 1 ] - h [ 0 ] ;
  for ( int i = 0 ;
  i < N - K + 1 ;
  i ++ ) {
    int value = h [ i + K - 1 ] - h [ i ] ;
    if ( value < min ) {
      min = value ;
    }
  }
  System . out . println ( min ) ;
}

public static void main ( String [ ] args ) throws IOException { BufferedReader bf = new BufferedReader ( new InputStreamReader ( System . in ) ) ; String [ ] str = bf . readLine ( ) . split ( " ▁ " ) ; int N = Integer . parseInt ( str [ 0 ] ) , K = Integer . parseInt ( str [ 1 ] ) ; int [ ] h = new int [ N ] ; for ( int i = 0 ; i < N ; i ++ ) { h [ i ] = Integer . parseInt ( bf . readLine ( ) ) ; } Arrays . sort ( h ) ; int min = h [ N - 1 ] - h [ 0 ] ; for ( int i = 0 ; i < N - K + 1 ; i ++ ) { int value = h [ i + K - 1 ] - h [ i ] ; if ( value < min ) { min = value ; } } System . out . println ( min ) ; }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (array_type element: (type_identifier) dimensions: (dimensions)) name: (identifier))) (throws (type_identifier)) body: (block (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (type_identifier) arguments: (argument_list (object_creation_expression type: (type_identifier) arguments: (argument_list (field_access object: (identifier) field: (identifier)))))))) (local_variable_declaration type: (array_type element: (type_identifier) dimensions: (dimensions)) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)) name: (identifier) arguments: (argument_list (string_literal))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (array_access array: (identifier) index: (decimal_integer_literal))))) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (array_access array: (identifier) index: (decimal_integer_literal)))))) (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 (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))))))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (array_access array: (identifier) index: (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: (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (decimal_integer_literal))) update: (update_expression (identifier)) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (array_access array: (identifier) index: (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (decimal_integer_literal))) right: (array_access array: (identifier) index: (identifier))))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (identifier))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))