#include<bits/stdc++.h>
#define int long long
using namespace std;
constexpr int mod=998244353;
signed main(){
    int n,m; cin>>n>>m;
    vector<int> change{1};
    while(change.back()<=n && change.back()<=m){
        change.push_back(n/(n/change.back())+1);
    }
    if(change.back()>m)change.back()=m+1;
    int ans=0;
    for(int i=0;i<change.size()-1;i++){
        int r=n/change[i];
        int s=(change[i+1]-change[i])*(change[i]+change[i+1]-1)/2%mod;
        int s2=r*(1+r)/2%mod;
        (ans+=s*r%mod+s2*s%mod)%=mod;
    }
    cout<<ans<<endl;
}