//Class Tavan
//Ali asadiyan
public class Tavan {
 private double a;
 private double b;
 public double TCalc(double a,double b){
  if (b < 0){ System.out.println("Error! (b) Must Be Greeter Than or equal 0");
  System.exit(0);}
  if (b <= 0  && a == 0) {System.out.println("Error!\n(b) Must Be "
  +"Greeter Than or equal 0 & (a) not a zero");
  System.exit(0);}
  if (b==0)return 1;
  else if (b==1) return a;
  return a*TCalc(a,b-1);
  }
 }

//Main Class TestTavan
//Ali asadiyan
import java.util.Scanner;
public class TestTavan {
 public static void main(String[] arg){
  Scanner R = new Scanner(System.in);
  Tavan t = new Tavan();
  System.out.print("Please Enter a:");
  double a = R.nextDouble();
  System.out.print("Please Enter b:");
  double b = R.nextDouble();
  System.out.println("a:"+(int)a);
  System.out.println("b:"+(int)b);
  System.out.println((int)a+"^"+(int)b+": "+t.TCalc(a , b));
 }
}