#include #include #include #include #include #include #include #include #include #include #include #include #define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl; #define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl; template inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; } template inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; } using namespace std; typedef long long ll; using T = tuple; int main(){ ios::sync_with_stdio(false); cin.tie(0); cout << setprecision(10) << fixed; int n; cin >> n; vector p(n), inv(n+1); for(int i = 0; i < n; i++) { cin >> p[i]; inv[p[i]] = i; } set st; for(int i = 1; i <= n; i++) st.insert(i); vector vp; for(int i = 0; i < n; i++){ vp.push_back(T(2*i+2, -p[i]-1, i)); vp.push_back(T(i+1, -p[i], i)); } sort(vp.begin(), vp.end(), greater()); ll ans = 0; vector ok(n); for(auto [score, x, i]: vp){ if(ok[i]) continue; if((i+1)*2 == score){ auto pt = st.upper_bound(p[i]); if(pt == st.end()){ continue; } ans += i+1; st.erase(pt); ok[i] = true; }else{ auto pt = st.lower_bound(p[i]); if(pt == st.end()){ ans -= i+1; st.erase(st.begin()); }else{ st.erase(pt); } ok[i] = true; } } cout << ans << endl; }