Even if that's so, modulus (or at least the concept of remainders) are elementary school math and any competent programmer could bang together an (inefficient) modulus operator in a few minutes.
So even in a language w/o a mod operator, it's not a hard problem if you understand how to solve problems with code.
So even in a language w/o a mod operator, it's not a hard problem if you understand how to solve problems with code.