#include <bits/stdc++.h> using namespace std; #define int long long constexpr int mod = 1e9 + 7; struct SegmentTree { int n; vector<int> t; SegmentTree(int _n) { n = _n; t.resize(4 * n); } int merge(int x, int y) { return x + y; } void update(int id, int tl, int tr, int i, int v) { if (tl == tr) { t[id] = v; return; } int x = (id << 1) + 1, y = x + 1, tm = (tl + tr) >> 1; if (i <= tm) { update(x, tl, tm, i, v); } else { update(y, tm + 1, tr, i, v); } t[id] = merge(t[x], t[y]); } int get(int id, int tl, int tr, int l, int r) { if (r < tl || tr < l) return 0LL; if (l <= tl && tr <= r) return t[id]; int x = (id << 1) + 1, y = x + 1, tm = (tl + tr) >> 1; return merge(get(x, tl, tm, l, r), get(y, tm + 1, tr, l, r)); } void update(int i, int v) { update(0, 0, n - 1, i, v); } int get(int l, int r) { return get(0, 0, n - 1, l, r); } }; signed main() { ios::sync_with_stdio(false); cin.tie(nullptr); int n; cin >> n; vector<int> a(n); for (int i = 0; i < n; i++) { cin >> a[i]; } auto b = a; ranges::sort(b); for (auto &x : a) { x = ranges::lower_bound(b, x) - b.begin() + 1; } SegmentTree t(n + 1); for (int i = 1; i <= n; i++) { t.update(i, 1); } vector<int> f(n + 1); f[0] = 1; for (int i = 1; i <= n; i++) { f[i] = f[i - 1] * i % mod; } int ans = 1; for (int i = 0; i < n; i++) { int cnt = t.get(1, a[i] - 1); ans = (ans + cnt * f[n - i - 1]) % mod; t.update(a[i], 0); } cout << ans << '\n'; return 0; }