#include<bits/stdc++.h>
#define int long long
using namespace std;
const int N=200100;
pair<int,int> a[N],b[N],c[N];
set<pair<int,int> >sa,sb;
int fa[N];
int find(int x){
	if(x==fa[x]) return x;
	return fa[x]=find(fa[x]);
}
void merge(int x,int y){
	x=find(x),y=find(y);
	if(x==y) return;
	fa[x]=y;
}
void solve(){
	int n;cin>>n;
	int t=0;
	for(int i=1;i<=n;i++){
		fa[i]=i;
		int x;cin>>x;
		a[i]={x,i};
		c[++t]={x,0};
		cin>>x;
		b[i]={x,i};
		c[++t]={x,1};
	}
	sort(c+1,c+t+1);
	int res=0;
	for(int i=1;i<=t/2;i++){
		res-=c[i].first;
	}
	int mx=1e13;
	for(int i=t/2+1;i<=t;i++) res+=c[i].first;
	for(int i=1;i<t;i++){
			mx=min(mx,c[i+1].first-c[i].first);
	}
	if(mx==1e13) mx=0;
	mx*=2;
	// res-=mx;
	int ans=0;
	for(int i=1;i<=n;i++) ans+=a[i].first-b[i].first;
	for(int i=1;i<=n;i++){
		sa.insert(a[i]);
		sb.insert(b[i]);
	}
	while(sa.size()&&sb.size()){
		auto p=sa.begin();
		auto [u1,v1]=*(p);
		auto q=sb.end();q--;
		auto [u2,v2]=*q;
		if(u1>=u2) break;
		if(find(v1)!=find(v2)){
			ans+=2*(u2-u1);
			merge(v1,v2);
			sa.erase(p);sb.erase(q);
		}
		else if(find(v1)==find(v2)&&sa.size()==1){
			ans+=2*(u2-u1);
			merge(v1,v2);
			sa.erase(p);sb.erase(q);
		}
		else{
			auto pp=p;
			pp++;
			auto qq=q;
			qq--;
			auto [u11,v11]=*pp;
			auto [u22,v22]=*qq;
				int x12=u22-u1,x21=u2-u11;
				int minx=max(x12,x21);
				if(minx<0){
					ans=res;
					break;
				}
				if(x12==minx){
					ans+=x12*2;
					merge(v1,v22);
					sa.erase(p);sb.erase(qq);
				}
				else if(x21==minx){
					ans+=x21*2;
					merge(v11,v2);
					sa.erase(pp);sb.erase(q);
				}
		}
	}
	cout<<ans<<"\n";
}

signed main(){
ios::sync_with_stdio(false);
cin.tie(0);cout.tie(0);
	solve();
}