#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <stdio.h>
#include <math.h>
#include <iostream>
#include <iomanip>
#include <vector>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <queue>
#include <string>
#include <stack>
#include <numeric>
#include <algorithm>
using namespace std;
using ll = long long;
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
#define rep(i, n) for (ll i = 0; i < n; i++)
#define ALL(a) (a).begin(), (a).end()
int main()
{
    int n, m;
    scanf("%d %d", &n, &m);
    mint ans0 = 0, ans1 = 0;
    mint jsum = 0;
    for (int j = 1; j <= m; j++)
    {
        const ll nr = n % j;
        jsum += j - 1;
        ans0 += n / j * jsum;
        ans1 += nr * (nr + 1);
    }
    ans0 += ans1 / 2;
    printf("%d\n", ans0.val());
    return 0;
}