238. A Function That Grows Too Fast

The Ackermann function is defined as:

A(0, n) = n + 1 A(m, 0) = A(m - 1, 1) A(m, n) = A(m - 1, A(m, n - 1))

Print A(m, n).

Read the third line carefully: the second argument of the outer call is itself a recursive call. That nesting is why this function cannot be rewritten as a simple loop, and it is the classic example of a function that is computable but not primitive recursive.

It also grows absurdly fast. A(4, 2) has 19,729 digits, so the constraints here are tiny on purpose.

Constraints - `0 ≤ m ≤ 3` - `0 ≤ n ≤ 6`