n = read_line.to_i
a = read_line.split.map(&.to_i64).sort
max = a.max
sum = Array.new(max * 3 + 1, 0i64)
cnt = Array.new(max * 3 + 1, 0i64)
ans = 0i64
n.times do |i|
  v = a[i]
  sum[v] = v
  cnt[v] = 1
  ans += v * (n - 1 - i)
end
1.upto(sum.size - 1) do |i|
  sum[i] += sum[i - 1]
  cnt[i] += cnt[i - 1]
end
a.each do |v|
  cur = v
  while cur <= max + v
    s = sum[cur + v - 1] - sum[cur]
    c = cnt[cur + v - 1] - cnt[cur]
    ans -= s - c * cur
    cur += v
  end
end
puts ans