public class Demonstrate {
 public static void main (String argv[]) {
  System.out.println (powerOf2 (4));
 }
 public static int powerOf2 (int n) {
  int counter, result;       
  for (counter = n, result = 1; counter != 0; --counter) {
    result = 2 * result;
  }
  return result;
 }
}