static int po ( int n ) {
  int a = 2 ;
  int res = 1 ;
  while ( n > 0 ) {
    if ( n % 2 == 0 ) {
      res *= a ;
      n -- ;
    }
    else {
      a *= a ;
      n /= 2 ;
    }
  }
  return res ;
}

static int po ( int n ) { int a = 2 ; int res = 1 ; while ( n > 0 ) { if ( n % 2 == 0 ) { res *= a ; n -- ; } else { a *= a ; n /= 2 ; } } return res ; }
(method_declaration (modifiers) type: (integral_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (integral_type) name: (identifier))) body: (block (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))) (while_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) 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: (identifier) right: (identifier))) (expression_statement (update_expression (identifier)))) alternative: (block (expression_statement (assignment_expression left: (identifier) right: (identifier))) (expression_statement (assignment_expression left: (identifier) right: (decimal_integer_literal))))))) (return_statement (identifier))))