#include <iostream>
#include <algorithm>
#include <iomanip>
#include <vector>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <tuple>
#include <cmath>
#include <numeric>
#include <functional>
#include <cassert>
#include <atcoder/modint>

#define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl;
#define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

using namespace std;
typedef long long ll;

template<typename T>
vector<vector<T>> vec2d(int n, int m, T v){
    return vector<vector<T>>(n, vector<T>(m, v));
}

template<typename T>
vector<vector<vector<T>>> vec3d(int n, int m, int k, T v){
    return vector<vector<vector<T>>>(n, vector<vector<T>>(m, vector<T>(k, v)));
}

template<typename T>
void print_vector(vector<T> v, char delimiter=' '){
    if(v.empty()) {
        cout << endl;
        return;
    }
    for(int i = 0; i+1 < v.size(); i++) cout << v[i] << delimiter;
    cout << v.back() << endl;
}

using mint = atcoder::modint998244353;

ostream& operator<<(ostream& os, const mint& m){
    os << m.val();
    return os;
}

vector<int> f(int n){
    vector<int> v;
    for(int x = 1; x*x <= n; x++){
        v.push_back(x);
        if(x*x != n) v.push_back(n/x);
    }
    sort(v.begin(), v.end());
    return v;
}

mint inv6 = mint(6).inv();
mint inv2 = mint(2).inv();

mint sum(int n){
    return mint(n)*mint(n+1)*inv2;
}

mint sum_sect(int l, int r){
    return sum(r)-sum(l-1);
}

mint sum_square(int n){
    return mint(n)*mint(n+1)*mint(2*n+1)*inv6;
}

// [l, r]
mint sum_square_sect(int l, int r){
    return sum_square(r)-sum_square(l-1);
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << setprecision(10) << fixed;
    int n, m; cin >> n >> m;
    mint ans = mint(n)*mint(n+1)*mint(m)/2;
    auto v = f(n+1);
    reverse(v.begin(), v.end());
    int pre = 0;
    for(int x: v){
        int l = pre+1;
        int r = (n+1)/x;
        chmin(r, m);
        if(r < l) continue;
        ans -= sum_square_sect(l, r)*sum(x-1);
        ans -= sum_sect(l, r)*(n+1)*x;
        ans += sum_square_sect(l, r)*x*x;
        pre = r;
    }
    cout << ans << endl;
}