#include <bits/stdc++.h>
#define int long long
#define INF 100000000
using namespace std;
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n;
cin>>n;
int cost = 0;
int mat[2*n+1][3];
for(int i = 0;i<=(2*n);i++){
for(int j = 0;j<3;j++) mat[i][j] = 0;
}
vector<int> coin[3], need[3];
for(int i = 0;i<(2*n);i++){
int x, y;
cin>>x>>y;
if(y<=1){
cost+=(1 - y);
y = 1;
}
else{
cost+=(y - 2);
y = 2;
}
if(x<1){
cost += (1 - x);
x = 1;
}
if(x>n){
cost += (x - n);
x = n;
}
mat[x][y]++;
}
for(int i = 1;i<=(2*n);i++){
for(int j = 1;j<=2;j++){
if(mat[i][j] == 0) need[j].push_back(i);
while(mat[i][j] > 1){
coin[j].push_back(i);
mat[i][j]--;
}
while(need[j].size() && coin[j].size()){
cost+=(abs(need[j].back() - coin[j].back()));
need[j].pop_back(); coin[j].pop_back();
}
}
for(int j = 1;j<=2;j++){
int k = j^3;
while(need[k].size() && coin[j].size()){
cost+=(abs(need[k].back() - coin[j].back()) + 1);
need[k].pop_back(); coin[j].pop_back();
}
}
//cout<<i<<endl;
}
cout<<cost<<endl;
}
/*
5
1000000000 1000000000
-1000000000 1000000000
-1000000000 -1000000000
1000000000 -1000000000
-1 -5
-2 2
2 8
4 7
-2 5
7 3
*/
