tail x num

• Type: int -> int -> int
• Description: Returns the last num digits of x. If there are fewer than num digits in x, return x in its entirety.
• Assumptions: num and x are both non-negative.
• Examples:

tail 154 1 = 4 tail 154 2 = 54 tail 154 3 = 154 tail 154 4 = 154 tail 154 0 = 0

Should be implemented by Ocaml. Try several ways to approach but can't update local variable in else statement.

Can someone help?