A. Power
time limit per test
1 s
memory limit per test
512 MB
input
pow.in
output
pow.out

You're given integers $$$a$$$ and $$$b$$$，calculate $$$a^b$$$。

But if $$$a^b$$$ exceeds $$$10^9$$$, print '-1'. Otherwise, print the correct value.

Input

Read from file "pow.in"

Single line contains integers $$$a, b$$$.

Output

Output to file "pow.out"

Single line,if $$$a^b$$$ doesn't exceeds $$$10^9$$$, print $$$a^b$$$, otherwise print '-1'.

Examples
Input
10 9
Output
1000000000
Input
23333 66666
Output
-1
Note

$$$$$$1 \le a, b \le 10^9$$$$$$