sgu 112 - a^b - b^a large numbers

112. a b -b a

time limit per test: 0.25 sec. 
memory limit per test: 4096 KB

You are given natural numbers a and b. Find ab-ba.

Input

Input contains numbers a and b (1≤a,b≤100).

Output

Write answer to output.

Sample Input

2 3

Sample Output

-1

Use scanner to TLE

import java.io. *;
import java.math.BigInteger;


public class Main {
    public static void main(String args[]) throws IOException {
        StreamTokenizer in = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));
        PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));

        BigInteger a;
        BigInteger b;
        in.nextToken();
        int A=(int) in.nval;
        in.nextToken();
        int B=(int) in.nval;

        a=BigInteger.valueOf(A);
        b=BigInteger.valueOf(B);
        out.println(a.pow(B).subtract(b.pow(A)));
        out.flush();
    }

}

a

while (in.nextToken() != StreamTokenizer.TT_EOF)

My ruby ​​A's posture is so ugly, I want to learn ruby, it's too bad

a=gets.split
x=a[0].to_i
y=a[1].to_i
print x**yy**x