#include <stdio.h>
int power_of_2 (int n) {
  int counter, result;
  for (counter = n, result = 1;         
       counter;                         
       --counter, result = result * 2)  
    ;                                   
  return result;
}
int recursive_power_of_2 (int n) {
  if (n == 0)
     return 1;
    else
     return 2 * power_of_2 (n - 1);  /**/
}
main ( ) {
 printf ("%i\n", recursive_power_of_2 (4));
}