#include <bits/stdc++.h>
using namespace std;
#define int long long
#define INF 1000000000000000000
#define MOD 998244353
int32_t main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
int n, x, y, ans = 0;
cin >> n;
int a[n][2];
memset(a, 0, sizeof(a));
for(int i = 0; i < 2*n; 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;
}
x--; y--;
a[x][y]++;
}
int i1 = 0, i2 = 0;
for(int i = 0; i < n; i++) {
while(i1 < n && a[i1][0] == 0) i1++;
while(i2 < n && a[i2][1] == 0) i2++;
if(i1 == n) {
ans += abs(i-i2);
a[i2][1]--;
while(i2 < n && a[i2][1] == 0) i2++;
ans += abs(i-i2)+1;
a[i2][1]--;
continue;
} else if(i2 == n) {
ans += abs(i-i1);
a[i1][0]--;
while(i1 < n && a[i1][0] == 0) i1++;
ans += abs(i-i1)+1;
a[i1][0]--;
continue;
}
if(i1 <= i && i2 > i) {
ans += abs(i-i1);
a[i1][0]--;
while(i1 < n && a[i1][0] == 0) i1++;
} else if(i2 <= i && i1 > i) {
ans += abs(i-i2)+1;
a[i2][1]--;
while(i2 < n && a[i2][1] == 0) i2++;
} else if(abs(i-i1) <= abs(i-i2)+1) {
ans += abs(i-i1);
a[i1][0]--;
while(i1 < n && a[i1][0] == 0) i1++;
} else {
ans += abs(i-i2)+1;
a[i2][1]--;
while(i2 < n && a[i2][1] == 0) i2++;
}
if(i1 <= i && i2 > i) {
ans += abs(i-i1)+1;
a[i1][0]--;
while(i1 < n && a[i1][0] == 0) i1++;
} else if(i2 <= i && i1 > i) {
ans += abs(i-i2);
a[i2][1]--;
while(i2 < n && a[i2][1] == 0) i2++;
} else if(abs(i-i2) <= abs(i-i1)+1) {
ans += abs(i-i2);
a[i2][1]--;
while(i2 < n && a[i2][1] == 0) i2++;
} else {
ans += abs(i-i1)+1;
a[i1][0]--;
while(i1 < n && a[i1][0] == 0) i1++;
}
}
cout << ans;
}
