public class power_i {
 
  // we would like to have a set of static methods that
  // compute powers such as x square, x cube etc...

  // square 
  public static int pow2(int x) {
    return x * x;
  }

  // cube
  public static int pow3(int x) {
    return x * x * x;
  }

  // 4th power
  public static int pow4(int x) {
    return x * x * x * x;
  }

  // generalization: n-th power
  // (works for n >= 0)
  public static int pown(int x, int n) {
    int result = 1;
    while (n > 0) {
      result *= x;
      n--;
    }
    return result;
  }

  // test our methods -> nice :-)
  public static void main(String a[]) {
    System.out.println(" 7^2 = " + pow2(7));
    System.out.println("10^3 = " + pow3(10));
    System.out.println(" 2^4 = " + pow4(2));
    System.out.println(" 2^5 = " + pown(2, 5));
  }

}