MOD = 998244353

n, m = map(int, input().split())
D = min(n, m)
S1 = 0
S2 = 0
d = 1

while d <= D:
    q = n // d
    if q == 0:
        break
    max_d = n // q
    current_end = min(max_d, D)
    num_terms = current_end - d + 1
    a = d
    l = current_end
    sum_d = (a + l) * num_terms // 2
    contribution_S2 = q * sum_d
    contribution_S1 = (q * (q + 1) // 2) * sum_d
    S2 = (S2 + contribution_S2) % MOD
    S1 = (S1 + contribution_S1) % MOD
    d = current_end + 1

total = (S1 + S2) % MOD
print(total)