#include <iostream>
#include <vector>
#include <algorithm>
#include <atcoder/modint>
using namespace std;
using ll = long long;
using ull = unsigned long long;
#define rep(i,n) for(int i=0; i<(n); i++)

using mll = atcoder::static_modint<998244353>;

int main(){
  ll n,m; cin >> n >> m;
  vector<ll> turn;
  turn.push_back(0);
  turn.push_back(m);
  for(ll k=1; k<=50000; k++) turn.push_back(k);
  for(ll k=1; k<=50000; k++) turn.push_back(n/k);
  sort(turn.begin(),turn.end());
  
  mll ans = 0;

  for(int i=1; i<turn.size(); i++){
    ll rk = turn[i];
    ll lk = turn[i-1];
    if(rk == lk) continue;
    if(rk > m) continue;
    ll maxi = n/rk;
    if(maxi == 0) continue;
    //cout << "k = (" << lk << "," << rk << "]" << endl;
    //cout << "maxi = " << maxi << endl;
    mll sumk = mll(rk)*(rk+1)/2 - mll(lk)*(lk+1)/2;
    //cout << "sumk = " << sumk.val() << endl;
    ans += sumk * (mll(maxi+2) * (maxi+1) / 2 - 1);
  }

  cout << ans.val() << "\n";
  return 0;
}

struct ios_do_not_sync{
  ios_do_not_sync(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
  }
} ios_do_not_sync_inst;