#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using mint = modint998244353;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vvvll = vector<vvll>;
using vmi = vector<mint>;
using vvmi = vector<vmi>;
using vvvmi = vector<vvmi>;
#define all(a) (a).begin(), (a).end()
#define rep2(i, m, n) for (int i = (m); i < (n); ++i)
#define rep(i, n) rep2(i, 0, n)
#define drep2(i, m, n) for (int i = (m)-1; i >= (n); --i)
#define drep(i, n) drep2(i, n, 0)
ll minq(ll base, ll a){
    ll left = 1, right = base;
    ll mid;
    while(right - left > 1){
        mid = (left+right)/2;
        if(base/mid > a){
            left = mid;
        }else{
            right = mid;
        }
    }
    return right;
}



int main(){

    ll n, m; cin >> n >> m;
    if(n == 1){
        cout << 0 << endl;
        return 0;
    }
    
    ll w = min(m-1, n);
    mint ans = mint(0);
    
    while(w > 1){
        ll p = m/w;
        ll low = minq(m, p);
        ll cnt = ((m%low) - (m%w))/p + 1;
        ans += mint(cnt)* (mint(m%w) + mint(m%low)) / mint(2);
        
        w = low-1;
    
    }
    if(n > m) ans += mint(m)*mint(n-m);
    cout << ans.val() << endl;
    
    return 0;
}