#include <bits/stdc++.h>
using namespace std;
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
int n;
cin >> n;
int64_t top[n],bot[n];
for(int i = 0;i < n;++i)
{
top[i] = 0;
bot[i] = 0;
}
int64_t ans = 0;
for(int i = 0;i < 2*n;++i)
{
int x,y;
cin >> x >> y;
int ind = 0;
if(x <= 1)
ind = 0;
else if(x >= n)
ind = n-1;
else
ind = x-1;
ans += abs(x-(ind+1));
if(y >= 2)
{
top[ind]++;
ans += abs(y-2);
}
else
{
bot[ind]++;
ans += abs(y-1);
}
}
// cout << ans << ' ';
int64_t f = 0,s = 0;
for(int i = 0;i < n;++i)
{
// cout << top[i] << ' ' << bot[i] << ' ' << f << ' ' << s << "\n";
if(f < i+1)
{
int64_t gl = min(i+1-f,top[i]);
ans += (i-f)*gl -(gl-1)*gl/2;
f += gl;
top[i] -= gl;
}
if(s < i+1)
{
int64_t gl = min(i+1-s,bot[i]);
ans += (i-s)*gl -(gl-1)*gl/2;
s += gl;
bot[i] -= gl;
}
// cout << top[i] << ' ' << bot[i] << ' ' << f << ' ' << s << "\n";
if(bot[i] && top[i])
{
ans += bot[i] + top[i];
bot[i+1] += bot[i];
top[i+1] += top[i];
}
else if(top[i] && !bot[i])
{
int64_t gl = min(i+1-s,top[i]);
ans += (i-s)*gl -(gl-1)*gl/2;
s += gl;
ans += gl;
top[i] -= gl;
ans += top[i];
top[i+1] += top[i];
}
else if(!top[i] && bot[i])
{
int64_t gl = min(i+1-f,bot[i]);
ans += (i-f)*gl -(gl-1)*gl/2;
f += gl;
ans += gl;
bot[i] -= gl;
ans += bot[i];
bot[i+1] += bot[i];
}
// cout << ans << "\n";
}
cout << ans << "\n";
return 0;
}
