#define _USE_MATH_DEFINES #include "bits/stdc++.h" using namespace std; #define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i)) #define rep(i,j) FOR(i,0,j) #define each(x,y) for(auto &(x):(y)) #define mp make_pair #define MT make_tuple #define all(x) (x).begin(),(x).end() #define debug(x) cout<<#x<<": "<<(x)<; using vi = vector; using vll = vector; template class ModInt { public: ModInt() :value(0) {} ModInt(long long val) :value((int)(val < 0 ? MOD + val % MOD : val % MOD)) { } ModInt& operator+=(ModInt that) { value = value + that.value; if (value >= MOD)value -= MOD; return *this; } ModInt& operator-=(ModInt that) { value -= that.value; if (value < 0)value += MOD; return *this; } ModInt& operator*=(ModInt that) { value = (int)((long long)value * that.value % MOD); return *this; } ModInt& operator/=(ModInt that) { return *this *= that.inverse(); } ModInt operator+(ModInt that) const { return ModInt(*this) += that; } ModInt operator-(ModInt that) const { return ModInt(*this) -= that; } ModInt operator*(ModInt that) const { return ModInt(*this) *= that; } ModInt operator/(ModInt that) const { return ModInt(*this) /= that; } ModInt pow(long long k) const { ModInt n = *this, res = 1; if (k < 0) { k = -k; n = n.inverse(); } while (k) { if (k & 1)res *= n; n *= n; k >>= 1; } return res; } ModInt inverse() const { long long a = value, b = MOD, u = 1, v = 0; while (b) { long long t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v); } return ModInt(u); } int toi() const { return value; } private: int value; }; typedef ModInt<998244353> mint; // 素数 ostream& operator<<(ostream & os, const mint & x) { os << x.toi(); return os; } void solve() { int N, M; cin >> N >> M; mint ans; for (int i = 1; i * i <= N && i <= M; ++i) { mint x = N / i; ans += ((x + 1) * x / 2 + x) * i; } for (int i = 1; i * i < N; ++i) { int lb = N / (i + 1) + 1; int ub = min(N / i, M); if (lb <= ub) { mint x = i; ans += ((x + 1) * x / 2 + x) * (ub + lb) * (ub - lb + 1) / 2; } } cout << ans << endl; } int main() { ios::sync_with_stdio(false); cin.tie(0); cout << fixed << setprecision(15); solve(); return 0; }