#include <cstdio>
#include <cstring>
#include <iostream>
#include <string>
#include <cmath>
#include <bitset>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <algorithm>
#include <complex>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <cassert>
#include <fstream>
#include <utility>
#include <functional>
#include <time.h>
#include <stack>
#include <array>
#include <list>
#include <atcoder/all>
#define popcount __builtin_popcount
using namespace std;
using namespace atcoder;
typedef long long ll;
typedef pair<int, int> P;
using mint=modint998244353;

int main()
{
    ll n, m;
    cin>>n>>m;
    vector<ll> v;
    for(ll x=1; (x-1)*(x-1)<=n; x++){
        v.push_back(x);
        v.push_back(n/x);
    }
    sort(v.begin(), v.end());
    v.erase(unique(v.begin(), v.end()), v.end());
    mint ans=0;
    mint inv2=mint(2).inv();
    auto calc=[&](ll r){
        return mint(r)*mint(r+1)*inv2;
    };
    for(auto x:v){
        ll r=min(n/x, m);
        if(n/(x+1)+1>r) continue;
        ans+=(mint(x)+calc(x))*(calc(r)-calc(n/(x+1)));
    }
    cout<<ans.val()<<endl;
    return 0;
}