## https://yukicoder.me/problems/no/2127

import math

MOD = 998244353

def main():
    N, M = map(int, input().split())

    sqrt_n = int(math.sqrt(N))

    inv_pow2 = pow(2, MOD - 2, MOD)
    inv_pow4 = pow(4, MOD - 2, MOD)
    inv_pow12 = pow(12, MOD - 2, MOD)

    # j がsqrt(N)以下のケース
    answer1 = 0
    for j in range(1, min(M, sqrt_n) + 1):
        r = N % j
        q = N // j

        ans1 = ((j - 1) * j) % MOD
        ans1 *= inv_pow2
        ans1 %= MOD
        ans1 *= q
        ans1 %= MOD

        ans2 = ((r + 1) * r) % MOD
        ans2 *= inv_pow2
        ans2 %= MOD
        
        ans = (ans1 + ans2) % MOD
        answer1 += ans
        answer1 %= MOD
    
    # q　がsqrt(N)以下のケース
    answer2 = 0
    if M > sqrt_n:
        def sum1(n):
            ans = (n * (n + 1)) % MOD
            ans *= (n - 1)
            ans %= MOD
            ans *= pow(6, MOD - 2, MOD)
            ans %= MOD
            return ans
        
        def sum2(n, N, q):
            ans1 = (q * q) % MOD
            ans1 *= n
            ans1 %= MOD
            ans1 *= (n + 1)
            ans1 %= MOD
            ans1 *= (((2 * n) % MOD) + 1) % MOD
            ans1 %= MOD
            ans1 *= inv_pow12
            ans1 %= MOD

            ans2 = (2 * N + 1) % MOD
            ans2 *= q
            ans2 %= MOD
            ans2 *= n
            ans2 %= MOD
            ans2 *= (n + 1)
            ans2 %= MOD
            ans2 *= inv_pow4
            ans2 %= MOD

            ans3 = (N * (N + 1)) % MOD
            ans3 *= n
            ans3 %= MOD
            ans3 *= inv_pow2
            ans3 %= MOD

            answer = (ans1 - ans2) % MOD
            answer += ans3
            answer %= MOD

            return answer

        add_start = False
        sqrt_n2 = N // sqrt_n
        for q in range(sqrt_n2 + 2):
            if q == 0:
                lower = N
                if M <= lower:
                    continue
                add_start = True
                upper = M
            else:
                lower = max(N // (q + 1), sqrt_n)
                if not add_start:
                    if M <= lower:
                        continue
                    add_start = True
                    upper = M
                else:
                    upper = max(N // q, sqrt_n)

            ans = (sum1(upper) - sum1(lower)) % MOD
            ans *= q
            ans %= MOD


            ans2 = (sum2(upper, N, q) - sum2(lower, N, q)) % MOD
            ans += ans2
            ans %= MOD
            answer2 += ans
            answer2 %= MOD

    answer = (answer1 + answer2) % MOD
    print(answer)
            

        
    
























if __name__ == "__main__":
    main()