import kotlin.math.*

// sum of A_j * (A_i / A_j)
fun helper(a: List<Int>): Long {
    val n = a.size
    val max = a.maxOrNull()!!
    val sqrt = sqrt(max.toDouble()).roundToInt()
    val l = Array(sqrt) { 0L }
    val bit = BIT(max + 1)
    var ans = 0L
    for (i in 0 until n) {
        if (a[i] < sqrt) {
            ans += l[a[i]]
        } else {
            for (k in 0..max step a[i]) {
                ans += k * bit.sum(k until minOf(k + a[i], max + 1))
            }
        }
        bit.add(a[i], 1)
        for (j in 1 until sqrt) {
            l[j] += a[i] / j * j.toLong()
        }
    }
    return ans
}

fun main() {
    val n = readInt()
    val a = readInts().sortedDescending()
    var ans = helper(a)
    for (i in 0 until n) {
        ans += (2 * i - n + 1L) * a[i]
    }
    println(ans)
}

class BIT(private val n: Int) {
    private val data = LongArray(n) { 0 }

    fun add(i: Int, x: Long) {
        var p = i + 1
        while (p <= n) {
            data[p - 1] += x
            p += p and -p
        }
    }

    fun sum(range: IntRange): Long {
        val l = range.first
        val r = range.last + 1
        return sum(r) - sum(l)
    }

    private fun sum(i: Int): Long {
        var r = i
        var s = 0L
        while(r > 0) {
            s += data[r - 1]
            r -= r and -r
        }
        return s
    }
}

fun readInt() = readln().toInt()
fun readInts() = readln().split(" ").map { it.toInt() }