public static void main ( String [ ] args ) throws IOException {
  String s = next ( ) ;
  int up = 0 ;
  int right = 0 ;
  for ( int i = 0 ;
  i < s . length ( ) ;
  i ++ ) {
    if ( s . charAt ( i ) == 'U' ) {
      up ++ ;
    }
    else if ( s . charAt ( i ) == 'D' ) {
      up -- ;
    }
    else if ( s . charAt ( i ) == 'L' ) {
      right -- ;
    }
    else {
      right ++ ;
    }
  }
  up = Math . abs ( up ) ;
  right = Math . abs ( right ) ;
  if ( ( up + right ) % 2 == 0 ) {
    pr . println ( ( up + right ) / 2 ) ;
  }
  else {
    pr . println ( - 1 ) ;
  }
  pr . close ( ) ;
}

public static void main ( String [ ] args ) throws IOException { String s = next ( ) ; int up = 0 ; int right = 0 ; for ( int i = 0 ; i < s . length ( ) ; i ++ ) { if ( s . charAt ( i ) == ' U ' ) { up ++ ; } else if ( s . charAt ( i ) == ' D ' ) { up -- ; } else if ( s . charAt ( i ) == ' L ' ) { right -- ; } else { right ++ ; } } up = Math . abs ( up ) ; right = Math . abs ( right ) ; if ( ( up + right ) % 2 == 0 ) { pr . println ( ( up + right ) / 2 ) ; } else { pr . println ( - 1 ) ; } pr . close ( ) ; }
(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: (method_invocation 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: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) update: (update_expression (identifier)) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))) right: (character_literal))) consequence: (block (expression_statement (update_expression (identifier)))) alternative: (if_statement condition: (parenthesized_expression (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))) right: (character_literal))) consequence: (block (expression_statement (update_expression (identifier)))) alternative: (if_statement condition: (parenthesized_expression (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))) right: (character_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))))) (expression_statement (assignment_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))))) (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) right: (decimal_integer_literal)) right: (decimal_integer_literal))) consequence: (block (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (binary_expression left: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) right: (decimal_integer_literal)))))) alternative: (block (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (unary_expression operand: (decimal_integer_literal))))))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))))