import java.io.PrintWriter
import java.util.*
import kotlin.math.*

fun PrintWriter.solve() {
    val n = nextInt()
    val m = nextInt()
    val a = Array(m) { nextInt() }
    val set = a.toSet()
    val isopen = Array(n + 1) { false }
    var count = 0
    for (i in n downTo 1) {
        if (set.contains(i) xor isopen[i]) {
            // region divisors
            val number = i
            val divs = mutableListOf<Int>()
            var divisor = 1
            while (divisor * divisor <= number) {
                if (number % divisor == 0) {
                    divs.add(divisor)
                    if (divisor * divisor != number) {
                        divs.add(number / divisor)
                    }
                }
                divisor++
            }
            // endregion
            for (d in divs) {
                isopen[d] = !isopen[d]
            }
        } else {
            count++
        }
    }
    println(count)
}

fun main() {
    Thread(null, {
        val writer = PrintWriter(System.out, false)
        writer.solve()
        writer.flush()
    }, "solve", abs(1L.shl(26)))
        .apply { setUncaughtExceptionHandler { _, e -> e.printStackTrace(); kotlin.system.exitProcess(1) } }
        .apply { start() }.join()
}

// region Scanner
private var st = StringTokenizer("")
private val br = System.`in`.bufferedReader()

fun next(): String {
    while (!st.hasMoreTokens()) st = StringTokenizer(br.readLine())
    return st.nextToken()
}

fun nextInt() = next().toInt()
fun nextLong() = next().toLong()
fun nextLine() = br.readLine()
fun nextDouble() = next().toDouble()
// endregion