Calculate the a ^ b WITHOUT using *, / and ^ Challenge
Your goal is, given two positive integer numbers a and b, to calculate (and output) a ^ b without using either multiplication, division and the power itself (not directly, at least).
And, of course, built-in exponentiation functions.
Scoring
This is code-golf, so the shorter, the better.
Test cases
Input =&gt; Output
2, 3 =&gt; 8
5, 5 =&gt; 3125
100, 4 =&gt; 100000000
17, 9 =&gt; 118587876497
0, 1 =&gt; 0
3921, 0 =&gt; 1
k (19 bytes)

This is slow and uses lots of memory:

{#,//(x#,:)/[y;0b]}


The /s are not division, it's the converge operator.