#include <bits/stdc++.h> using namespace std; using ll = long long; ll INF = 1e18; ll n; vector<pair<ll, ll>> s; vector<vector<ll>> pref; ll an(ll x, ll y) { ll ans = 0; pref.assign(2, vector<ll>(n, 0)); for (ll i = 0; i < s.size(); i++) { if (s[i].first < x) { if (s[i].second <= y) { ans += abs(x - s[i].first) + abs(y - s[i].second); pref[1][0]++; continue; } else { ans += abs(x - s[i].first) + abs((y + 1) - s[i].second); pref[0][0]++; continue; } } if (s[i].first > x + n - 1) { if (s[i].second <= y) { ans += abs((x + n - 1) - s[i].first) + abs(y - s[i].second); pref[1][n - 1]++; continue; } else { ans += abs((x + n - 1) - s[i].first) + abs((y + 1) - s[i].second); pref[0][n - 1]++; continue; } } if (y + 1 <= s[i].second) { ans += abs((y + 1) - s[i].second); pref[0][s[i].first - x]++; } else { ans += abs((y) - s[i].second); pref[1][s[i].first - x]++; } } deque<ll> d1, d2; deque<ll> cool1, cool2; for (ll j = 0; j < n; j++) { if (pref[0][j] == 0) { d1.push_back(j); } if (pref[1][j] == 0) { d2.push_back(j); } if (!cool1.empty() && !d1.empty()) { ans += abs(j - cool1.front()); cool1.pop_front(); d1.pop_front(); } if (!cool2.empty() && !d2.empty()) { ans += abs(j - cool2.front()); cool2.pop_front(); d2.pop_front(); } if (!cool1.empty() && !d2.empty()) { ans += abs(j - cool1.front()) + 1; cool1.pop_front(); d2.pop_front(); } if (!cool2.empty() && !d1.empty()) { ans += abs(j - cool2.front()) + 1; cool2.pop_front(); d1.pop_front(); } while (!d1.empty() && pref[0][j] > 1) { ans += j - d1.front(); d1.pop_front(); pref[0][j]--; } if (d1.empty() && pref[0][j] > 1) { for (ll e = 1; e < pref[0][j]; e++) { cool1.push_back(j); } } while (!d2.empty() && pref[1][j] > 1) { ans += j - d2.front(); d2.pop_front(); pref[1][j]--; } if (d2.empty() && pref[1][j] > 1) { for (ll e = 1; e < pref[1][j]; e++) { cool2.push_back(j); } } while (!cool1.empty() && !d2.empty()) { ans += abs(d2.front() - cool1.front()) + 1; cool1.pop_front(); d2.pop_front(); } while (!cool2.empty() && !d1.empty()) { ans += abs(d1.front() - cool2.front()) + 1; cool2.pop_front(); d1.pop_front(); } } return ans; } int main() { ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr); cin >> n; s.assign(n * 2, {}); for (ll i = 0; i < n * 2; i++) { cin >> s[i].first >> s[i].second; } cout << an(1, 1); } // 3 // 0 0 // 0 4 // 4 0 // 2 1 // 2 5 // -1 1