#include <stdio.h>
int power_of_2 (int n) {
  int counter, result;
  for (counter = n, result = 1;         /* Initialization  */
       counter;                         /* Test            */
       --counter, result = result * 2)  /* Reassignment    */
    ;                                   /* Empty statement */
  return result;
}
main ( ) {
 printf ("%i\n", power_of_2 (4));
}