#include <bits/stdc++.h>
using namespace std;
#define rep(i, n)  for(long long i=0;i<(long long)(n);i++)
#define REP(i,k,n) for(long long i=k;i<(long long)(n);i++)
#define all(a) a.begin(),a.end()
#define pb push_back
#define eb emplace_back
#define lb(v,k) (lower_bound(all(v),k)-v.begin())
#define ub(v,k) (upper_bound(all(v),k)-v.begin())
#define fi first
#define se second
#define pi M_PI
#define PQ(T) priority_queue<T>
#define SPQ(T) priority_queue<T,vector<T>,greater<T>>
#define dame(a) {out(a);return 0;}
#define decimal cout<<fixed<<setprecision(15);
typedef long long ll;
typedef pair<ll,ll> P;
typedef tuple<ll,ll,ll> PP;
typedef tuple<ll,ll,ll,ll> PPP;
typedef multiset<ll> S;
using vi=vector<ll>;
using vvi=vector<vi>;
using vvvi=vector<vvi>;
using vp=vector<P>;
using vvp=vector<vp>;
using vb=vector<bool>;
using vvb=vector<vb>;
const ll inf=1001001001001001;
const int INF=1001001001;
const int mod=1000000007;
const double eps=1e-10;
template<class T> bool chmin(T&a,T b){if(a>b){a=b;return true;}return false;}
template<class T> bool chmax(T&a,T b){if(a<b){a=b;return true;}return false;}
template<class T> void out(T a){cout<<a<<'\n';}
template<class T> void outp(T a){cout<<'('<<a.fi<<','<<a.se<<')'<<'\n';}
template<class T> void outvp(T v){rep(i,v.size())cout<<'('<<v[i].fi<<','<<v[i].se<<')';cout<<'\n';}
template<class T> void outvvp(T v){rep(i,v.size())outvp(v[i]);}
template<class T> void outv(T v){rep(i,v.size()){if(i)cout<<' ';cout<<v[i];}cout<<'\n';}
template<class T> void outvv(T v){rep(i,v.size())outv(v[i]);}
template<class T> bool isin(T x,T l,T r){return (l)<=(x)&&(x)<=(r);}
template<class T> void yesno(T b){if(b)out("yes");else out("no");}
template<class T> void YesNo(T b){if(b)out("Yes");else out("No");}
template<class T> void YESNO(T b){if(b)out("YES");else out("NO");}
template<class T> void noyes(T b){if(b)out("no");else out("yes");}
template<class T> void NoYes(T b){if(b)out("No");else out("Yes");}
template<class T> void NOYES(T b){if(b)out("NO");else out("YES");}
void outs(ll a,ll b){if(a>=inf-100)out(b);else out(a);}
ll gcd(ll a,ll b){if(b==0)return a;return gcd(b,a%b);}
ll modpow(ll a,ll b){a%=mod;if(b==0)return 1;if(b&1)return a*modpow(a,b-1)%mod;ll k=modpow(a,b/2);return k*k%mod;}
int main(){
    ll n;cin>>n;
    vp l(n),r(n);
    rep(i,n)cin>>l[i].fi>>r[i].fi;
    rep(i,n){l[i].se=i;r[i].se=i;}
    sort(all(l));reverse(all(l));
    sort(all(r));
    ll ans=0;
    if(r[0].fi<0){
        vb used(n,false);
        ll res=-r[0].fi,wl=0,wr=0,w=r[0].fi;
        used[r[0].se]=true;
        while(true){
            while(wl<n){
                if(used[l[wl].se])wl++;
                else break;
            }
            if(wl>=n)break;
            used[l[wl].se]=true;
            if(l[wl].fi>w){
                res+=l[wl].fi-w;
                w=l[wl].fi;
            }
            //cout<<w<<' '<<res<<endl;
            while(wr<n){
                if(used[r[wr].se])wr++;
                else break;
            }
            if(wr>=n)break;
            used[r[wr].se]=true;
            if(r[wr].fi<w){
                res+=w-r[wr].fi;
                w=r[wr].fi;
            }
            //cout<<w<<' '<<res<<endl;
        }
        res+=abs(w);
        chmax(ans,res);
    }
    //out(ans);
    if(l[0].fi>0){
        ll res=l[0].fi,wl=0,wr=0,w=l[0].fi;
        vb used(n,false);
        used[l[0].se]=true;
        while(true){
            while(wr<n){
                if(used[r[wr].se])wr++;
                else break;
            }
            if(wr>=n)break;
            used[r[wr].se]=true;
            if(r[wr].fi<w){
                res+=w-r[wr].fi;
                w=r[wr].fi;
            }
            while(wl<n){
                if(used[l[wl].se])wl++;
                else break;
            }
            if(wl>=n)break;
            used[l[wl].se]=true;
            if(l[wl].fi>w){
                res+=l[wl].fi-w;
                w=l[wl].fi;
            }
        }
        res+=abs(w);
        chmax(ans,res);
    }
    out(ans);
}

Measured memory_bytes: 3328