#include #include using namespace atcoder; #define rep(i, n) for (int i = 0; i < (n); ++i) using namespace std; using mint = modint998244353; struct modinv { int n; vector d; modinv(): n(2), d({0,1}) {} mint operator()(int i) { while (n <= i) d.push_back(-d[mint::mod()%n]*(mint::mod()/n)), ++n; return d[i]; } mint operator[](int i) const { return d[i];} } invs; struct modfact { int n; vector d; modfact(): n(2), d({1,1}) {} mint operator()(int i) { while (n <= i) d.push_back(d.back()*n), ++n; return d[i]; } mint operator[](int i) const { return d[i];} } facts; struct modfactinv { int n; vector d; modfactinv(): n(2), d({1,1}) {} mint operator()(int i) { while (n <= i) d.push_back(d.back()*invs(n)), ++n; return d[i]; } mint operator[](int i) const { return d[i];} } ifacts; mint f(int a, int b) { mint res = facts(a+b)*ifacts(a-2)*ifacts(b-2)*invs(a)*invs(b)*invs(a+b-1); return res*res; } int main() { int n; cin >> n; mint ans; for (int k = 2; k <= n-2; ++k) { ans += f(n-k, k); } cout << ans.val() << '\n'; return 0; }