n-th digit of a number

Write a function DigitN(k, n) that returns the $n$-th digit from the right of a natural number $k$ ($n = 1$ is the units digit). If $k$ has fewer than $n$ digits, it returns $-1$. Use it to answer $q$ queries.

The first line contains $q$ ($1 \le q \le 1000$). Each of the next $q$ lines contains $k$ and $n$ (, ).

$q$ lines: DigitN(k, n) for each query.

Integer-divide by $10$ $n - 1$ times — the last digit is the one you need. If the number has become $0$ by then, there is no such digit. In the first example: $12345$ has no 7th digit ($-1$), the 4th digit of $$ is , the 5th digit of is .