import java.math.*;

public class BigPower {

    public static void main (String[] argv)
    {
        BigInteger X = new BigInteger ("3");
        BigInteger Y = new BigInteger ("2");
        BigInteger Z = power (X, Y);
        BigInteger Z2 = power2 (X, Y);
        System.out.println (X + "^" + Y + " = " + Z + " Z2=" + Z2);

        X = new BigInteger ("2");
        Y = new BigInteger ("8");
        Z = power (X, Y);
        Z2 = power2 (X, Y);
        System.out.println (X + "^" + Y + " = " + Z + " Z2=" + Z2);


        X = new BigInteger ("2");
        Y = new BigInteger ("1000");
        Z = power (X, Y);
        Z2 = power2 (X, Y);
        System.out.println (X + "^" + Y + " = " + Z + " Z2=" + Z2);
    }


    static BigInteger zero = new BigInteger ("0");
    static BigInteger one = new BigInteger ("1");

    static BigInteger power (BigInteger A, BigInteger B)
    {
        if ( B.equals(zero) ) {
            return new BigInteger ("1");
        }
        BigInteger BMinus1 = B.subtract (one);
        BigInteger temp = power (A, BMinus1);
        BigInteger P = A.multiply (temp);
        return P;
    }

}