public static void main ( String [ ] args ) throws IOException {
  FastScanner input = new FastScanner ( ) ;
  long l = input . nextLong ( ) ;
  long r = input . nextLong ( ) ;
  long store [ ] = new long [ 1025 ] ;
  for ( int i = 2 ;
  i <= 1024 ;
  i ++ ) {
    if ( i % 2 == 0 ) {
      store [ i ] = 10 * store [ i / 2 ] + 4 ;
    }
    else {
      store [ i ] = 10 * store [ i / 2 ] + 7 ;
    }
  };
}

public static void main ( String [ ] args ) throws IOException { FastScanner input = new FastScanner ( ) ; long l = input . nextLong ( ) ; long r = input . nextLong ( ) ; long store [ ] = new long [ 1025 ] ; for ( int i = 2 ; i <= 1024 ; i ++ ) { if ( i % 2 == 0 ) { store [ i ] = 10 * store [ i / 2 ] + 4 ; } else { store [ i ] = 10 * store [ i / 2 ] + 7 ; } } ; }
(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)))) (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 (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: (decimal_integer_literal)) update: (update_expression (identifier)) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (identifier) right: (decimal_integer_literal)) right: (decimal_integer_literal))) consequence: (block (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (binary_expression left: (binary_expression left: (decimal_integer_literal) right: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal)))) right: (decimal_integer_literal))))) alternative: (block (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (binary_expression left: (binary_expression left: (decimal_integer_literal) right: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal)))) right: (decimal_integer_literal))))))))))