Exponential Calculation Warning

Given two positive integers \(a\) and \(b\), compute \(a^b\), which means multiplying \(a\) by itself \(b\) times. For example, \(2^3\) is \(2 \times 2 \times 2 = 8\).

If \(a^b\) exceeds \(10^9\), output \(-1\) as a warning to avoid potential overflow issues.

inputFormat

The input consists of a single line containing two positive integers (a) and (b) separated by a space.

outputFormat

Output the value of (a^b) if it does not exceed (10^9); otherwise, output (-1).

sample

2 3

8