import io.StdIn._

object Main extends App {
  val line1 = readLine.split(" ").map(_.toInt)
  val N = line1(0)
  val P = line1(1)

  val S = readLine.toCharArray.map(_.toInt - 48)

  val d = Array.fill[Int](N + 1)(0)
  var ten = 1
  for (i <- N - 1 to 0 by -1) {
    val a = S(i) * ten % P
    d(i) = (d(i + 1) + a) % P
    ten = ten * 10 % P
  }

  val cnt = Array.fill[Int](P)(0)
  var ans = 0L
  for (i <- N to 0 by -1) {
    ans = ans + cnt(d(i))
    cnt(d(i)) = cnt(d(i)) + 1
  }

  println(ans)
}
