#include<iostream>
#include<cstring>
#include<algorithm>
using namespace std;
const int N = 1e6+10,mod=998244353;
typedef long long LL;
int main(){
	LL n,m;
	LL ans=0;
	scanf("%lld%lld",&n,&m);
	for(LL i=1,j;i<=m;i=j+1){
		LL t=n/i;
		if(t==0)break;
		j=min(n/t,m);
		LL sum=(j-i+1)*(j+i)/2;
		ans+=sum*(t+t*(t+1)/2)%mod;
		ans%=mod;
	}
	cout<<ans;
	return 0;
}