#include #include using namespace std; #if __has_include() #include using namespace atcoder; #endif using ll = long long; using ld = long double; using ull = long long; #define REP3(i, m, n) for (int i = (m); (i) < int(n); ++ (i)) #define ALL(x) begin(x), end(x) #define all(s) (s).begin(),(s).end() #define rep2(i, m, n) for (int i = (m); i < (n); ++i) #define rep(i, n) rep2(i, 0, n) #define drep2(i, m, n) for (int i = (m)-1; i >= (n); --i) #define drep(i, n) drep2(i, n, 0) #define rever(vec) reverse(vec.begin(), vec.end()) #define sor(vec) sort(vec.begin(), vec.end()) #define fi first #define se second #define P pair #define REP(i, n) for (int i = 0; i < (n); ++i) #define in scanner.read_int() const ll mod = 998244353; //const ll mod = 1000000007; const ll inf = 2000000000000000000ll; static const long double pi = 3.141592653589793; templatevoid vcin(vector &n){for(int i=0;i>n[i];} templatevoid vcout(vector &n){for(int i=0;i void chmax(T& t,const U& u){if(t void chmin(T& t,const U& u){if(t>u) t=u;} template void ifmin(T t,T u){if(t>u){cout<<-1< void ifmax(T t,T u){if(t>u){cout<<-1<auto make_vector(T x,int arg,Args ...args){if constexpr(sizeof...(args)==0)return vector(arg,x);else return vector(arg,make_vector(x,args...));} ll modPow(ll a, ll n, ll mod) { ll ret = 1; ll p = a % mod; while (n) { if (n & 1) ret = ret * p % mod; p = p * p % mod; n >>= 1; } return ret; } void gbjsmzmfuuvdf(){ ios::sync_with_stdio(false); std::cin.tie(nullptr); cout<< fixed << setprecision(20); } class Scanner { vector buffer; ssize_t n_written; ssize_t n_read; public: Scanner(): buffer(1024*1024) { do_read(); } int64_t read_int() { int64_t ret = 0, sgn = 1; int ch = current_char(); while (isspace(ch)) { ch = next_char(); } if (ch == '-') { sgn = -1; ch = next_char(); } for (; isdigit(ch); ch = next_char()) ret = (ret * 10) + (ch - '0'); return sgn * ret; } private: void do_read() { ssize_t r = read(0, &buffer[0], buffer.size()); if (r < 0) { throw runtime_error(strerror(errno)); } n_written = r; n_read = 0; } inline int next_char() { ++n_read; if (n_read == n_written) { do_read(); } return current_char(); } inline int current_char() { return (n_read == n_written) ? EOF : buffer[n_read]; } }; int main() { Scanner scanner; gbjsmzmfuuvdf(); ll n,m; n=in; m=in; ll ans=0; ll k=0; for(ll i=1;i*i<=n&&i<=m;i++){ ans+=i*(n/i)%mod*(n/i+3)%mod*modPow(2,mod-2,mod); ans%=mod; chmax(k,i); } ll q=k+1; for(ll i=n/q;i>=1;i--){ ll s=n/i-n/(i+1); ll p=q+s-1; p=min(p,m); s=max(0ll,p-q+1); ans+=(p+q)*s%mod*modPow(2,mod-2,mod)%mod*i%mod*(i+3)%mod*modPow(2,mod-2,mod); ans%=mod; if(s==0){ break; } q=p+1; } cout<