#include <iostream>
#include <vector>
using namespace std;
#include <atcoder/modint>

int main() {
    int N, M;
    cin >> N >> M;
    M = min(M, N);
    atcoder::modint998244353 ret = 0;
    for (int i = 1; i <= M;) {
        int n = N / i;
        int j = min(M, N / n);
        ret += (n + (long long)n * (n + 1) / 2) * (i + j) * (j - i + 1);
        i = j + 1;
    }
    cout << (ret / 2).val() << '\n';
}