#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5;
int n, x, y, i;
int m[N][3], a, b;
long long ans;
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n;
for(i=1; i<=(n<<1); ++i){
cin >> x >> y;
if(x < 1) ans += 1 - x, x = 1;
else if(x > n) ans += x - n, x = n;
if(y < 1) ans += 1 - y, y = 1;
else if(y > 2) ans += y - 2, y = 2;
++m[x][y];
}
for(i=1; i<=n; ++i){
a += m[i][1] - 1, b += m[i][2] - 1;
while(a > 0 and b < 0) --a, ++b, ++ans;
while(a < 0 and b > 0) ++a, --b, ++ans;
ans += abs(a) + abs(b);
}
cout << ans;
}
