#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
using std::cout;
using std::cin;
using std::endl;
using ll=long long;
using ld=long double;
ll ILL=2167167167167167167;
const int INF=2100000000;
const ll mod=998244353;
#define rep(i,a) for (ll i=0;i<a;i++)
#define all(p) p.begin(),p.end()
template<class T> using _pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> ll LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> ll UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
void yneos(bool a){if(a) cout<<"Yes\n"; else cout<<"No\n";}
template<class T> void vec_out(vector<T> &p){for(int i=0;i<(int)(p.size());i++){if(i) cout<<" ";cout<<p[i];}cout<<"\n";}
template<class T> T min(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmin(ans,x);return ans;}
template<class T> T max(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmax(ans,x);return ans;}
template<class T> T sum(vector<T> &a){assert(!a.empty());T ans=a[0]-a[0];for(auto &x:a) ans+=x;return ans;}



void solve();
// oddloop
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	
	int t=1;
	//cin>>t;
	rep(i,t) solve();
}

void solve(){
	ll N,M;
	cin>>N>>M;
	ll rev_6=(mod+1)/6;
	ll ans=M*((((N+1)*N)/2)%mod);
	ans%=mod;
	auto f=[&](ll R,ll B)->ll{// [0,R]
		chmin(R,M);
		ll ans=0;
		ll tmp=(B*(N+1))%mod;
		ans=(tmp*(((R*(R+1))/2)%mod))%mod;
		tmp=((B*B)+B)/2;
		tmp%=mod;
		tmp=(tmp*R)%mod;
		tmp=(tmp*(R+1))%mod;
		tmp=(tmp*(2*R+1))%mod;
		tmp=(tmp*rev_6)%mod;
		return (ans-tmp)%mod;
	};
	chmin(M,N);
	ll r=N,l=N/2;
	ll b=1;
	while(r>40000){
		ans-=(f(r,b)-f(l,b));
		ans%=mod;
		b++;
		r=N/b;
		l=N/(b+1);
	}
	while(r){
		b=N/r;
		ans-=(f(r,b)-f(r-1,b));
		ans%=mod;
		r--;
	}
	cout<<(ans+mod)%mod<<"\n";
}