#include using namespace std; typedef long long int64; const int base = 1000000000; const int base_digits = 9; struct bigint { vector a; int64_t sign; bigint() : sign(1) {} bigint(long long v) { *this = v; } bigint(const string &s) { read(s); } void operator=(const bigint &v) { sign = v.sign; a = v.a; } void operator=(long long v) { sign = 1; if (v < 0) sign = -1, v = -v; for (; v > 0; v = v / base) a.push_back(v % base); } bigint operator+(const bigint &v) const { if (sign == v.sign) { bigint res = v; for (int64_t i = 0, carry = 0; i < (int64_t)max(a.size(), v.a.size()) || carry; ++i) { if (i == (int64_t)res.a.size()) res.a.push_back(0); res.a[i] += carry + (i < (int64_t)a.size() ? a[i] : 0); carry = res.a[i] >= base; if (carry) res.a[i] -= base; } return res; } return *this - (-v); } bigint operator-(const bigint &v) const { if (sign == v.sign) { if (abs() >= v.abs()) { bigint res = *this; for (int64_t i = 0, carry = 0; i < (int64_t)v.a.size() || carry; ++i) { res.a[i] -= carry + (i < (int64_t)v.a.size() ? v.a[i] : 0); carry = res.a[i] < 0; if (carry) res.a[i] += base; } res.trim(); return res; } return -(v - *this); } return *this + (-v); } void operator*=(int64_t v) { if (v < 0) sign = -sign, v = -v; for (int64_t i = 0, carry = 0; i < (int64_t)a.size() || carry; ++i) { if (i == (int64_t)a.size()) a.push_back(0); long long cur = a[i] * (long long)v + carry; carry = (int64_t)(cur / base); a[i] = (int64_t)(cur % base); // asm("divl %%ecx" : "=a"(carry), "=d"(a[i]) : "A"(cur), "c"(base)); } trim(); } bigint operator*(int64_t v) const { bigint res = *this; res *= v; return res; } friend pair divmod(const bigint &a1, const bigint &b1) { int64_t norm = base / (b1.a.back() + 1); bigint a = a1.abs() * norm; bigint b = b1.abs() * norm; bigint q, r; q.a.resize(a.a.size()); for (int64_t i = a.a.size() - 1; i >= 0; i--) { r *= base; r += a.a[i]; int64_t s1 = r.a.size() <= b.a.size() ? 0 : r.a[b.a.size()]; int64_t s2 = r.a.size() <= b.a.size() - 1 ? 0 : r.a[b.a.size() - 1]; int64_t d = ((long long)base * s1 + s2) / b.a.back(); r -= b * d; while (r < 0) r += b, --d; q.a[i] = d; } q.sign = a1.sign * b1.sign; r.sign = a1.sign; q.trim(); r.trim(); return make_pair(q, r / norm); } bigint operator/(const bigint &v) const { return divmod(*this, v).first; } bigint operator%(const bigint &v) const { return divmod(*this, v).second; } void operator/=(int64_t v) { if (v < 0) sign = -sign, v = -v; for (int64_t i = (int64_t)a.size() - 1, rem = 0; i >= 0; --i) { long long cur = a[i] + rem * (long long)base; a[i] = (int64_t)(cur / v); rem = (int64_t)(cur % v); } trim(); } bigint operator/(int64_t v) const { bigint res = *this; res /= v; return res; } int64_t operator%(int64_t v) const { if (v < 0) v = -v; int64_t m = 0; for (int64_t i = a.size() - 1; i >= 0; --i) m = (a[i] + m * (long long)base) % v; return m * sign; } void operator+=(const bigint &v) { *this = *this + v; } void operator-=(const bigint &v) { *this = *this - v; } void operator*=(const bigint &v) { *this = *this * v; } void operator/=(const bigint &v) { *this = *this / v; } bool operator<(const bigint &v) const { if (sign != v.sign) return sign < v.sign; if (a.size() != v.a.size()) return a.size() * sign < v.a.size() * v.sign; for (int64_t i = a.size() - 1; i >= 0; i--) if (a[i] != v.a[i]) return a[i] * sign < v.a[i] * sign; return false; } bool operator>(const bigint &v) const { return v < *this; } bool operator<=(const bigint &v) const { return !(v < *this); } bool operator>=(const bigint &v) const { return !(*this < v); } bool operator==(const bigint &v) const { return !(*this < v) && !(v < *this); } bool operator!=(const bigint &v) const { return *this < v || v < *this; } void trim() { while (!a.empty() && !a.back()) a.pop_back(); if (a.empty()) sign = 1; } bool isZero() const { return a.empty() || (a.size() == 1 && !a[0]); } bigint operator-() const { bigint res = *this; res.sign = -sign; return res; } bigint abs() const { bigint res = *this; res.sign *= res.sign; return res; } long long longValue() const { long long res = 0; for (int64_t i = a.size() - 1; i >= 0; i--) res = res * base + a[i]; return res * sign; } friend bigint gcd(const bigint &a, const bigint &b) { return b.isZero() ? a : gcd(b, a % b); } friend bigint lcm(const bigint &a, const bigint &b) { return a / gcd(a, b) * b; } void read(const string &s) { sign = 1; a.clear(); int64_t pos = 0; while (pos < (int64_t)s.size() && (s[pos] == '-' || s[pos] == '+')) { if (s[pos] == '-') sign = -sign; ++pos; } for (int64_t i = s.size() - 1; i >= pos; i -= base_digits) { int64_t x = 0; for (int64_t j = max(pos, i - base_digits + 1); j <= i; j++) x = x * 10 + s[j] - '0'; a.push_back(x); } trim(); } friend istream &operator>>(istream &stream, bigint &v) { string s; stream >> s; v.read(s); return stream; } friend ostream &operator<<(ostream &stream, const bigint &v) { if (v.sign == -1) stream << '-'; stream << (v.a.empty() ? 0 : v.a.back()); for (int64_t i = (int64_t)v.a.size() - 2; i >= 0; --i) stream << setw(base_digits) << setfill('0') << v.a[i]; return stream; } static vector convert_base(const vector &a, int64_t old_digits, int64_t new_digits) { vector p(max(old_digits, new_digits) + 1); p[0] = 1; for (int64_t i = 1; i < (int64_t)p.size(); i++) p[i] = p[i - 1] * 10; vector res; long long cur = 0; int64_t cur_digits = 0; for (int64_t i = 0; i < (int64_t)a.size(); i++) { cur += a[i] * p[cur_digits]; cur_digits += old_digits; while (cur_digits >= new_digits) { res.push_back(signed(cur % p[new_digits])); cur /= p[new_digits]; cur_digits -= new_digits; } } res.push_back((signed)cur); while (!res.empty() && !res.back()) res.pop_back(); return res; } typedef vector vll; static vll karatsubaMultiply(const vll &a, const vll &b) { int64_t n = a.size(); vll res(n + n); int64_t k = n >> 1; vll a1(a.begin(), a.begin() + k); vll a2(a.begin() + k, a.end()); vll b1(b.begin(), b.begin() + k); vll b2(b.begin() + k, b.end()); vll a1b1 = karatsubaMultiply(a1, b1); vll a2b2 = karatsubaMultiply(a2, b2); for (int64_t i = 0; i < k; i++) a2[i] += a1[i]; for (int64_t i = 0; i < k; i++) b2[i] += b1[i]; vll r = karatsubaMultiply(a2, b2); for (int64_t i = 0; i < (int64_t)a1b1.size(); i++) r[i] -= a1b1[i]; for (int64_t i = 0; i < (int64_t)a2b2.size(); i++) r[i] -= a2b2[i]; for (int64_t i = 0; i < (int64_t)r.size(); i++) res[i + k] += r[i]; for (int64_t i = 0; i < (int64_t)a1b1.size(); i++) res[i] += a1b1[i]; for (int64_t i = 0; i < (int64_t)a2b2.size(); i++) res[i + n] += a2b2[i]; return res; } bigint operator*(const bigint &v) const { vector a6 = convert_base(this->a, base_digits, 6); vector b6 = convert_base(v.a, base_digits, 6); vll a(a6.begin(), a6.end()); vll b(b6.begin(), b6.end()); while (a.size() < b.size()) a.push_back(0); while (b.size() < a.size()) b.push_back(0); while (a.size() & (a.size() - 1)) a.push_back(0), b.push_back(0); vll c = karatsubaMultiply(a, b); bigint res; res.sign = sign * v.sign; for (int64_t i = 0, carry = 0; i < (int64_t)c.size(); i++) { long long cur = c[i] + carry; res.a.push_back((int64_t)(cur % 1000000)); carry = (int64_t)(cur / 1000000); } res.a = convert_base(res.a, 6, base_digits); res.trim(); return res; } }; template struct BinaryIndexedTree { vector data; BinaryIndexedTree(int sz) { data.assign(++sz, 0); } T sum(int k) { T ret = 0; for (++k; k > 0; k -= k & -k) ret += data[k]; return (ret); } void add(int k, T x) { for (++k; k < data.size(); k += k & -k) data[k] += x; } }; int N, A[1000000]; int64 beet[1000001]; void input() { cin >> N; for (int i = 0; i < N; i++) cin >> A[i]; } pair rec(int a, int b) { if (a + 1 >= b) return {bigint(beet[a]), bigint(a + 1)}; int mid = (a + b) >> 1; auto v = rec(a, mid); auto t = rec(mid, b); t.first *= v.second; t.first += v.first; t.second *= v.second; return t; } signed main() { input(); BinaryIndexedTree bit(N + 1); for (int i = 0; i < N; i++) { --A[i]; bit.add(A[i], 1); } for (int i = 0; i < N; i++) { int64 sum = bit.sum(A[i] - 1); beet[N - i - 1] += sum; bit.add(A[i], -1); } cout << bigint(rec(0, N).first + 1) << endl; }