MOD = 998244353i64
n, m = read_line.split.map(&.to_i)
k = {n, m}.min
is_prime = Array.new(k + 1, true)
mu = Array.new(k + 1, 1)
mu[0] = 0
ans = tri(n.to_i64) * tri(m.to_i64) % MOD
2.upto(k) do |i|
  if is_prime[i]
    (i * 2).step(to: k, by: i) do |j|
      is_prime[j] = false
      mu[j] *= -1
    end
    mu[i] *= -1
    mu[i * i] = 0 if i.to_i64 * i <= k
  end
  if mu[i] == 0
    (i * 2).step(to: k, by: i) do |j|
      mu[j] = 0
    end
  end
  ans += tri(n.to_i64 // i) * tri(m.to_i64 // i) % MOD * mu[i] * i % MOD * i
  ans %= MOD
end
ans += MOD if ans < 0
puts ans

def tri(x : Int64)
  x * (x + 1) // 2 % MOD
end