Poj Solution 2109

http://poj.org/problem?id=2109

import java.math.BigInteger;
import java.util.Scanner;

public class Main {
 
    static final BigInteger TWO = new BigInteger("2");
    static final BigInteger ONE = BigInteger.ONE;

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // k^n=p findK;
          BigInteger p;
          int n;
        BigInteger ks, kl;
        while (in.hasNextInt()) {
            boolean find=false;
            n = in.nextInt();
            p = in.nextBigInteger();
            ks = ONE;
            kl = p;
            while (ks.compareTo(kl) <= 0) {
                BigInteger mid = ks.add(kl).divide(TWO);
                int ret = mid.pow(n).compareTo(p);
                if (ret == 0) {
                    find=true;
                    System.out.println(mid);
                    break;
                } else if (ret == -1) {
                    ks = mid.add(ONE);
                } else {
                    kl = mid.subtract(ONE);
                }
            }
            if(!find){
                System.out.println(ks.subtract(ONE));
            }
        }

    }
}