public static void main ( String [ ] args ) {
  Scanner sc = new Scanner ( System . in ) ;
  char [ ] s = sc . next ( ) . toCharArray ( ) ;
  long Bcnt = 0 ;
  long cnt = 0 ;
  for ( int i = 0 ;
  i < s . length ;
  i ++ ) {
    if ( s [ i ] == 'W' ) cnt += Bcnt ;
    if ( s [ i ] == 'B' ) Bcnt ++ ;
  }
  System . out . println ( cnt ) ;
}

public static void main ( String [ ] args ) { Scanner sc = new Scanner ( System . in ) ; char [ ] s = sc . next ( ) . toCharArray ( ) ; long Bcnt = 0 ; long cnt = 0 ; for ( int i = 0 ; i < s . length ; i ++ ) { if ( s [ i ] == ' W ' ) cnt += Bcnt ; if ( s [ i ] == ' B ' ) Bcnt ++ ; } System . out . println ( cnt ) ; }
(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: (array_type element: (integral_type) 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)))) (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: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (field_access object: (identifier) field: (identifier))) update: (update_expression (identifier)) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (character_literal))) consequence: (expression_statement (assignment_expression left: (identifier) right: (identifier)))) (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (character_literal))) consequence: (expression_statement (update_expression (identifier)))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))