static long find ( long n ) {
  if ( n == 1 ) return 1 ;
  long ans = 1 ;
  for ( int i = 1 ;
  i <= n ;
  i ++ ) {
    ans *= 2 ;
  }
  return ans + find ( n - 1 ) ;
}

static long find ( long n ) { if ( n == 1 ) return 1 ; long ans = 1 ; for ( int i = 1 ; i <= n ; i ++ ) { ans *= 2 ; } return ans + find ( n - 1 ) ; }
(method_declaration (modifiers) type: (integral_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (integral_type) name: (identifier))) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) consequence: (return_statement (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: (identifier)) update: (update_expression (identifier)) body: (block (expression_statement (assignment_expression left: (identifier) right: (decimal_integer_literal))))) (return_statement (binary_expression left: (identifier) right: (method_invocation name: (identifier) arguments: (argument_list (binary_expression left: (identifier) right: (decimal_integer_literal))))))))