static long factorial ( int n ) {
  if ( n == 0 ) return 1 ;
  if ( n < 0 ) return - 1 ;
  long res = 1 ;
  for ( int i = 2 ;
  i < n + 1 ;
  ++ i ) res *= i ;
  return res ;
}

static long factorial ( int n ) { if ( n == 0 ) return 1 ; if ( n < 0 ) return - 1 ; long res = 1 ; for ( int i = 2 ; i < n + 1 ; ++ i ) res *= i ; return res ; }
(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))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) consequence: (return_statement (unary_expression operand: (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: (binary_expression left: (identifier) right: (decimal_integer_literal))) update: (update_expression (identifier)) body: (expression_statement (assignment_expression left: (identifier) right: (identifier)))) (return_statement (identifier))))