<p>Your task is to calculate <code>a<sup>b</sup></code> mod <code>1337</code> where <code>a</code> is a positive integer and <code>b</code> is an extremely large positive integer given in the form of an array.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> a = 2, b = [3]
<strong>Output:</strong> 8
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> a = 2, b = [1,0]
<strong>Output:</strong> 1024
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> a = 1, b = [4,3,3,8,5,2]
<strong>Output:</strong> 1
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= a &lt;= 2<sup>31</sup> - 1</code></li>
	<li><code>1 &lt;= b.length &lt;= 2000</code></li>
	<li><code>0 &lt;= b[i] &lt;= 9</code></li>
	<li><code>b</code> does not contain leading zeros.</li>
</ul>

class Solution:
    def superPow(self, a: int, b: List[int]) -> int:
        def powmod(a, k):
            result = 1
            a %= 1337
            for _ in range(k):
                result = (result * a) % 1337
            return result
        
        def superPow(a, b):
            if not b:
                return 1
            last_digit = b.pop()
            part1 = powmod(a, last_digit)
            part2 = powmod(superPow(a, b), 10)
            return (part1 * part2) % 1337
        
        return superPow(a % 1337, b)

# Example usage:
solution = Solution()
a = 2
b = [3]
print(solution.superPow(a, b))  # Output: 8

a = 2
b = [1, 0]
print(solution.superPow(a, b))  # Output: 1024

a = 1
b = [4, 3, 3, 8, 5, 2]
print(solution.superPow(a, b))  # Output: 1
16900