#include<bits/stdc++.h>
using namespace std;
const int N = 1e6 + 7;
const int mod = 998244353;
typedef long long ll;
ll n;
int tot, siz, cnt;
int vis[N], prime[N];
int id1[N], id2[N];
ll g1[N], g2[N], w[N], s1[N], s2[N];

ll get(ll x) {
    if (x <= siz)return id1[x];
    return id2[n / x];
}

void seive() {
    for (int i = 2; i < N; i++) {
        if (!vis[i]) {
            prime[++tot] = i;
        }
        for (int j = 1; j <= tot && i * prime[j] < N; j++) {
            vis[i * prime[j]] = 1;
            if (i % prime[j] == 0)break;
        }
    }
    for (int i = 1; i <= tot; i++)s1[i] = (s1[i - 1] + prime[i]) % mod;
    for (int i = 1; i <= tot; i++)s2[i] = (s2[i - 1] + 1ll * prime[i] * prime[i]) % mod;
}

int kuasum(int a, int b) {
    int ans = 1;
    while (b) {
        if (b & 1)ans = 1ll * ans * a % mod;
        b >>= 1;
        a = 1ll * a * a % mod;
    }
    return ans;
}

ll p2(ll x) {
    x %= mod;
    return x * x % mod;
}

ll get2(ll x) {
    x %= mod;
    return (x * (x + 1) % mod * kuasum(2, mod - 2) % mod + mod - 1) % mod;
}

ll get3(ll x) {
    ll a = x % mod, b = (x + 1) % mod, c = (2 * x + 1) % mod;
    return (a * b % mod * c % mod * kuasum(6, mod - 2) % mod + mod - 1) % mod;
}

signed main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cin >> n;
    siz = sqrt(n);
    seive();
    for (ll l = 1, r; l <= n; l = r + 1) {
        r = n / (n / l);
        ll x = n / l;
        if (x <= siz)id1[x] = ++cnt;
        else id2[n / x] = ++cnt;
        w[cnt] = x;
        g1[cnt] = get2(x);
        g2[cnt] = get3(x);
    }
    for (int i = 1; i <= tot; i++) {
        for (int j = 1; j <= cnt && 1ll * prime[i] * prime[i] <= w[j]; j++) {
            ll nxt = w[j] / prime[i];
            int id = get(nxt);
            // cout << nxt<<" "<<id << " " << s1[i-1 ] << "\n";
            g1[j] = (g1[j] - 1ll * prime[i] * (g1[id] - s1[i - 1]) % mod + mod) % mod;
            g2[j] = (g2[j] - (1ll * prime[i] * prime[i] % mod) * (g2[id] - s2[i - 1]) % mod + mod) % mod;
        }
    }
    // for (int i = 1; i <= cnt; i++)cout << w[i] << " " << g1[i] << " " << g2[i] << "\n";
    ll ans = (get2(n) * get2(n) % mod - get3(n) + mod) * kuasum(2, mod - 2) % mod;

    ll sum1 = (g1[get(n)] - g1[get(n / 2)] + mod) % mod;
    ll sum2 = (g2[get(n)] - g2[get(n / 2)] + mod) % mod;
    // cout << sum1 << " " << sum2 << " " << ans << "\n";
    ll res = (sum1 * sum1 % mod + sum2) * kuasum(2, mod - 2) % mod;
    ans = (ans + res - get2(n) * sum1 % mod + mod) % mod;
    cout << ans << "\n";
    return 0;
}