public static void main ( String [ ] args ) {
  FastScanner input = new FastScanner ( ) ;
  int n = input . nextInt ( ) ;
  int k = input . nextInt ( ) ;
  int a [ ] = new int [ n ] ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    a [ i ] = input . nextInt ( ) ;
  }
  if ( n <= k ) {
    System . out . println ( a [ n - 1 ] ) ;
  }
  else {
    int i = 0 ;
    int j = n - ( k * 2 - n ) - 1 ;
    int max = Integer . MIN_VALUE ;
    while ( i <= j ) {
      max = Math . max ( max , a [ i ] + a [ j ] ) ;
      i ++ ;
      j -- ;
    }
    max = Math . max ( max , a [ a . length - 1 ] ) ;
    System . out . println ( max ) ;
  }
}

public static void main ( String [ ] args ) { FastScanner input = new FastScanner ( ) ; int n = input . nextInt ( ) ; int k = input . nextInt ( ) ; int a [ ] = new int [ n ] ; for ( int i = 0 ; i < n ; i ++ ) { a [ i ] = input . nextInt ( ) ; } if ( n <= k ) { System . out . println ( a [ n - 1 ] ) ; } else { int i = 0 ; int j = n - ( k * 2 - n ) - 1 ; int max = Integer . MIN_VALUE ; while ( i <= j ) { max = Math . max ( max , a [ i ] + a [ j ] ) ; i ++ ; j -- ; } max = Math . max ( max , a [ a . length - 1 ] ) ; System . out . println ( max ) ; } }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (array_type element: (type_identifier) dimensions: (dimensions)) name: (identifier))) body: (block (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (type_identifier) arguments: (argument_list)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) dimensions: (dimensions) 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)))))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) consequence: (block (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))))))) alternative: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (binary_expression left: (identifier) right: (parenthesized_expression (binary_expression left: (binary_expression left: (identifier) right: (decimal_integer_literal)) right: (identifier)))) right: (decimal_integer_literal)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (field_access object: (identifier) field: (identifier)))) (while_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) body: (block (expression_statement (assignment_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier) (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (array_access array: (identifier) index: (identifier))))))) (expression_statement (update_expression (identifier))) (expression_statement (update_expression (identifier))))) (expression_statement (assignment_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier) (array_access array: (identifier) index: (binary_expression left: (field_access object: (identifier) field: (identifier)) right: (decimal_integer_literal))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))))