public static void main ( String [ ] args ) {
  Scanner input = new Scanner ( System . in ) ;
  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 ( 0 ) ;
  }
  else {
    int ans = 0 ;
    for ( int i = 0 ;
    i < k ;
    i ++ ) {
      int count_1 = 0 ;
      int count_2 = 0 ;
      for ( int j = i ;
      j < n ;
      j += k ) {
        if ( a [ j ] == 1 ) {
          count_1 ++ ;
        }
        else {
          count_2 ++ ;
        }
      }
      ans += Math . min ( count_2 , count_1 ) ;
    }
    System . out . println ( ans ) ;
  }
}

public static void main ( String [ ] args ) { Scanner input = new Scanner ( System . in ) ; 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 ( 0 ) ; } else { int ans = 0 ; for ( int i = 0 ; i < k ; i ++ ) { int count_1 = 0 ; int count_2 = 0 ; for ( int j = i ; j < n ; j += k ) { if ( a [ j ] == 1 ) { count_1 ++ ; } else { count_2 ++ ; } } ans += Math . min ( count_2 , count_1 ) ; } System . out . println ( ans ) ; } }
(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 (field_access object: (identifier) field: (identifier)))))) (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: (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)))))) (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 (decimal_integer_literal))))) alternative: (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 (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: (decimal_integer_literal))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (identifier))) condition: (binary_expression left: (identifier) right: (identifier)) update: (assignment_expression left: (identifier) right: (identifier)) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (decimal_integer_literal))) consequence: (block (expression_statement (update_expression (identifier)))) alternative: (block (expression_statement (update_expression (identifier))))))) (expression_statement (assignment_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier) (identifier))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))))