#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pll;
#define fastio ios::sync_with_stdio(false), cin.tie(0)
// #pragma GCC optimize("Ofast")
#define pb push_back
#define eb emplace_back
#define f first
#define s second
#define lowbit(x) x&-x
const int maxn = 3000 + 5;
const int INF = 1e9;
const double eps = 1e-7;
int cnt[maxn][2];
int main(void){
fastio;
int n;
cin>>n;
ll ans = 0;
for(int i = 0; i < 2 * n; i++){
int x, y;
cin>>x>>y;
x--, y--;
if(y >= 1) ans += y - 1, y = 1;
else ans += -y, y = 0;
if(x >= n - 1) ans += x - n + 1, x = n - 1;
else if(x < 0) ans += -x, x = 0;
cnt[x][y]++;
}
for(int j = 0; j < 2; j++){
for(int i = 0; i < n; i++) cnt[i][j] -= 1;
}
vector<int> dist(2), cur(2);
//see operations as moving boxed
for(int i = 0; i < n; i++){
ans += abs(cur[0]) + abs(cur[1]);
cur[0] += cnt[i][0], cur[1] += cnt[i][1];
if(cur[0] > 0 && cur[1] < 0){
int trade = min(cur[0], -cur[1]);
ans += trade;
cur[0] -= trade, cur[1] += trade;
}
if(cur[1] > 0 && cur[0] < 0){
int trade = min(-cur[0], cur[1]);
ans += trade;
cur[0] += trade, cur[1] -= trade;
}
}
cout<<ans<<"\n";
}
