#include #include #define rep(i,n) for(int i=0;i vi; typedef vector vl; typedef vector> vvi; typedef vector> vvl; typedef long double ld; typedef pair P; ostream& operator<<(ostream& os, const modint& a) {os << a.val(); return os;} template ostream& operator<<(ostream& os, const static_modint& a) {os << a.val(); return os;} template istream& operator>>(istream& is, vector& v){int n = v.size(); assert(n > 0); rep(i, n) is >> v[i]; return is;} template ostream& operator<<(ostream& os, const pair& p){os << p.first << ' ' << p.second; return os;} template ostream& operator<<(ostream& os, const vector& v){int n = v.size(); rep(i, n) os << v[i] << (i == n - 1 ? "\n" : " "); return os;} template ostream& operator<<(ostream& os, const vector>& v){int n = v.size(); rep(i, n) os << v[i] << (i == n - 1 ? "\n" : ""); return os;} template void chmin(T& a, T b){a = min(a, b);} template void chmax(T& a, T b){a = max(a, b);} using mint = modint998244353; // combination mod prime // https://youtu.be/8uowVvQ_-Mo?t=6002 // https://youtu.be/Tgd_zLfRZOQ?t=9928 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 comb(int n, int k) { if (n < k || k < 0) return 0; return facts(n)*ifacts(k)*ifacts(n-k); } using S = int; S op(S a, S b){ return a + b; } S e(){ return 0; } int main(){ int n; cin >> n; vector p(n); cin >> p; rep(i, n) p[i]--; vector s1(n), s2(n), l1(n), l2(n); { segtree seg(n); rep(i, n){ s1[i] = seg.prod(p[i], n); l1[i] = seg.prod(0, p[i]); seg.set(p[i], 1); } } { reverse(p.begin(), p.end()); segtree seg(n); rep(i, n){ s2[i] = seg.prod(p[i], n); l2[i] = seg.prod(0, p[i]); seg.set(p[i], 1); } reverse(s2.begin(), s2.end()); reverse(l2.begin(), l2.end()); reverse(p.begin(), p.end()); } mint ans = 0; rep(i, n){ // cout << s1[i] << ' ' << l1[i] << ' ' << s2[i] << ' ' << l2[i] << "\n"; ans += comb(s1[i] + l2[i], min(s1[i], l2[i])) * comb(s2[i] + l1[i], min(s2[i], l1[i])); } cout << ans << "\n"; return 0; }