#ifndef LOCAL
#include <bits/stdc++.h>

using namespace std;

#define debug(...) (void(0))
#else
#include "algo/debug.h"
#endif

#include <atcoder/modint>
using mint = atcoder::modint998244353;
mint arith(mint a0, mint d, mint len) {
    return (a0 * 2 + (len - 1) * d) * len / 2;
}
void solve() {
    int64_t N, M;
    cin >> N >> M;
    vector<int64_t> thr;
    vector<mint> sum{0};
    for (int64_t i = 1; i < N;) {
        int64_t lo = i, hi = N;
        while (hi > lo + 1) {
            int64_t mi = (lo + hi) / 2;
            (M / mi == M / i ? lo : hi) = mi;
        }
        thr.push_back(i);
        sum.push_back(sum.back() + arith(M % i, -M / i, lo - i + 1));
        if (i == hi) break;
        i = hi;
    }
    const auto g = [&](int64_t r) -> mint {
        if (r <= 0) return 0;
        int64_t hi = r, lo = 0;
        while (hi > lo + 1) {
            int64_t mi = (hi + lo) / 2;
            (M / mi == M / r ? hi : lo) = mi;
        }
        int64_t k = distance(thr.begin(), lower_bound(thr.begin(), thr.end(), hi));
        mint ans = sum[k];
        ans += arith(M % hi, -M / hi, r - hi + 1);
        return ans;
    };
    mint ans = g(N);
    cout << ans.val() << endl;
}

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    int tt = 1;
    // std::cin >> tt;
    while (tt--) {
        solve();
    }
}