/*
+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+
|:\/\/:|:\/\/:|:\/\/:|:\/\/:|:\/\/:|:\/\/:|:\/\/:|:\/\/:|:\/\/:|:\/\/:|:\/\/:|:\/\/:|:\/\/:|:\/\/:|:\/\/:|:\/\/:|:\/\/:|
|\/\/\/|\/\/\/|\/\/\/|\/\/\/|\/\/\/|\/\/\/|\/\/\/|\/\/\/|\/\/\/|\/\/\/|\/\/\/|\/\/\/|\/\/\/|\/\/\/|\/\/\/|\/\/\/|\/\/\/|
|/:/\:\|/:/\:\|/:/\:\|/:/\:\|/:/\:\|/:/\:\|/:/\:\|/:/\:\|/:/\:\|/:/\:\|/:/\:\|/:/\:\|/:/\:\|/:/\:\|/:/\:\|/:/\:\|/:/\:\|
+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+
|\:\/:/|\:\/:/|\:\/:/|\:\/:/|\:\/:/|\:\/:/|\:\/:/|\:\/:/|\:\/:/|\:\/:/|\:\/:/|\:\/:/|\:\/:/|\:\/:/|\:\/:/|\:\/:/|\:\/:/|
|/\/\/\|/\/\/\|/\/\/\|/\/\/\|/\/\/\|/\/\/\|/\/\/\|/\/\/\|/\/\/\|/\/\/\|/\/\/\|/\/\/\|/\/\/\|/\/\/\|/\/\/\|/\/\/\|/\/\/\|
|:/\/\:|:/\/\:|:/\/\:|:/\/\:|:/\/\:|:/\/\:|:/\/\:|:/\/\:|:/\/\:|:/\/\:|:/\/\:|:/\/\:|:/\/\:|:/\/\:|:/\/\:|:/\/\:|:/\/\:|
+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+
*/
#include <bits/stdc++.h>
#define fore(i, a, b) for (signed i = (a), i##_last = (b); i < i##_last; ++i)
#define fort(i, a, b) for (signed i = (a), i##_last = (b); i <= i##_last; ++i)
#define ford(i, a, b) for (signed i = (a), i##_last = (b); i >= i##_last; --i)
#define fi first
#define se second
#define pb push_back
#define sz(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
using namespace std;
using ll = long long;
using ld = long double;
template<class A, class B> bool maxi(A &a, const B &b) {return (a < b) ? (a = b, true):false;};
template<class A, class B> bool mini(A &a, const B &b) {return (a > b) ? (a = b, true):false;};
typedef unsigned long long ull;
typedef pair<int, int> ii;
typedef vector<ll> vi;
typedef vector<ii> vii;
typedef vector<vi> vvi;
typedef vector<vii> vvii;
const int maxN = 1e6 + 5;
int n;
vii p;
ll res;
array<int, maxN> x, y;
int main() {
ll mxy;
#ifdef LOCAL
freopen("input.INP", "r", stdin);
#endif // LOCAL
cin.tie(0) -> sync_with_stdio(0);
cout.tie(0);
cin >> n;
fort(i, 1, n) {
cin >> x[i] >> y[i];
p.emplace_back(-(x[i] >> 1), y[i] >> 1);
}
sort(all(p));
mxy = p.front().se;
fore(i, 1, n) {
res += mxy * (p[i].fi - p[i - 1].fi);
maxi(mxy, p[i].se);
}
(res += (-p.back().fi) * mxy) <<= 2;
cout << res << '\n';
return 0;
}
