// Starcraft 2 enjoyer //
#include <bits/stdc++.h>
// #pragma GCC target("avx2")
// #pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")
using namespace std;
#define LSOne(X) ((X) & -(X))
#define int long long
const int N = 2e5 + 5;
const int M = 2e6 + 5;
const int O = 1e6;
const long long K = 2;
const int LG = 60;
const long long INF = 1e18 + 5;
const int C = 26;
const int B = 1000;
const int MOD = 1e9 + 7;
int n, ans, cnt[2][N], top, bot;
pair<int, int> p[N];
int dis(int a, int b, int x, int y)
{
return abs(a - x) + abs(b - y);
}
inline void solve()
{
cin >> n;
ans = 0;
for (int x = 0; x < 2 * n; x++)
{
int a, b;
cin >> a >> b;
int c, d;
if (a > n)
{
c = n;
}
else if (a < 1)
{
c = 1;
}
else
{
c = a;
}
if (b > 2)
{
d = 2;
}
else if (b < 1)
{
d = 1;
}
else
{
d = b;
}
ans += dis(a, b, c, d);
cnt[d - 1][c]++;
}
for (int x = 1; x <= n; x++)
{
top += cnt[0][x] - 1;
bot += cnt[1][x] - 1;
if (top > 0 && bot < 0)
{
ans += min(abs(top), abs(bot));
if (abs(top) > abs(bot))
{
top += bot;
bot = 0;
}
else
{
bot += top;
top = 0;
}
}
else if (top < 0 && bot > 0)
{
ans += min(abs(top), abs(bot));
if (abs(top) > abs(bot))
{
top += bot;
bot = 0;
}
else
{
bot += top;
top = 0;
}
}
ans += abs(bot) + abs(top);
}
cout << ans << "\n";
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int t = 1;
// cin >> t;
for (int x = 1; x <= t; x++)
{
solve();
}
return 0;
}
