#include using namespace std; //*/ #include using namespace atcoder; // //*/ #pragma GCC optimize("Ofast,unroll-loops,no-stack-protector,fast-math") #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt") #pragma GCC target("avx,avx2,fma") #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma") #define rep(i,n) for(int i=0;i; using ll = long long; using ull = unsigned long long; //*/ template inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; } template inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; } typedef pair pii; typedef pair pll; typedef vector vll; typedef vector vint; random_device rnd; mt19937 rng(rnd()); using mint = modint998244353; void solve(){ ll n; cin >> n; assert(n <= 1e7); mint ans = 0; for(ll i = 1;i <= n;i++){ ll m = sqrt(i); mint tmp = 0; for(ll j = 1;j <= m;j++) tmp += i/j; ans += 2*tmp-m*m; } cout << ans.val() << endl; } int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int t = 1; //cin >> t; rep(testcase,t) solve(); }