#include <bits/stdc++.h>
using namespace std;
#define Rep(i,n) for(int i=0;i<(int)(n);i++)
#define For(i,n1,n2) for(int i=(int)(n1);i<(int)(n2);i++)
#define REP(i,n) for(ll i=0;i<(ll)(n);i++)
#define RREP(i,n) for(ll i=((ll)(n)-1);i>=0;i--)
#define FOR(i,n1,n2) for(ll i=(ll)(n1);i<(ll)(n2);i++)
#define RFOR(i,n1,n2) for(ll i=((ll)(n1)-1);i>=(ll)(n2);i--)
#define all(a)  (a).begin(),(a).end()
#define SORT(a) sort((a).begin(),(a).end())
#define oorret 0
#define oor(x) [&](){try{x;} catch(const out_of_range& oor){return oorret;} return x;}()
#define IOS cin.tie(0),ios::sync_with_stdio(false)
typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll, ll> P;
template<typename T1, typename T2> inline bool chmin(T1& a, T2 b) { if (a > b) { a = b; return 1; }return 0; }
template<typename T1, typename T2> inline bool chmax(T1& a, T2 b) { if (a < b) { a = b; return 1; }return 0; }
template<class Type>struct is_vector : std::false_type {};
template<class ValueType, class Alloc>struct is_vector<std::vector<ValueType, Alloc>> : std::true_type {};
template <typename T> inline ostream& operator << (ostream& out, const vector<T>& v) {
	if (v.empty())return out;
	constexpr bool is_vector_v = is_vector<T>::value;
	if (is_vector_v)for (auto itr = v.begin(); itr != v.end();)out << (*itr), out << ((++itr != v.end()) ? "\n" : "");
	else for (auto itr = v.begin(); itr != v.end();)out << (*itr), out << ((++itr != v.end()) ? " " : "");
	return out;
}
inline void put() {}
template<class T> inline void put(const T& first) { std::cout << first << "\n"; }
template<class T, class... N> inline void put(const T& first, const N& ... rest) { std::cout << first << " "; put(rest...); }
inline void putn() {}
template<class T, class... N> inline void putn(const T& first, const N& ... rest) { std::cout << first << "\n"; putn(rest...); }


int main() {
	ll n;
	cin >> n;
	vector<ll> l(n), r(n);
	REP(i, n) {
		cin >> l[i] >> r[i];
	}
	vector<P> p1(n), p2(n);
	REP(i, n) {
		p1[i] = P(l[i], i);
		p2[i] = P(r[i], i);
	}
	sort(all(p1));
	sort(all(p2));
	vector<int> tl(n, 0), tr(n, 0);
	REP(i, n) {
		tl[i] = p1[i].second;
		tr[i] = p2[i].second;
	}
	reverse(all(tl));
	ll res = 0;
	ll tmp = 0;
	int cl = 0, cr = 0;
	int now = 0;
	vector<int> u(n, 0);
	REP(i, n) {
		if (i % 2 == 0) {
			while (u[tl[cl]] == 1) {
				cl++;
			}
			u[tl[cl]] = 1;
			int ind = tl[cl];
			if (now < l[ind]) {
				tmp += l[ind] - now;
				now = l[ind];
			} else if (r[ind] < now) {
				tmp += now - r[ind];
				now = r[ind];
			}
		} else {
			while (u[tr[cr]] == 1) {
				cr++;
			}
			u[tr[cr]] = 1;
			int ind = tr[cr];
			if (now < l[ind]) {
				tmp += l[ind] - now;
				now = l[ind];
			} else if (r[ind] < now) {
				tmp += now - r[ind];
				now = r[ind];
			}
		}
	}
	tmp += abs(now);
	chmax(res, tmp);
	tmp = 0;
	cl = cr = 0;
	now = 0;
	fill(all(u), 0);
	REP(i, n) {
		if (i % 2 == 1) {
			while (u[tl[cl]] == 1) {
				cl++;
			}
			u[tl[cl]] = 1;
			int ind = tl[cl];
			if (now < l[ind]) {
				tmp += l[ind] - now;
				now = l[ind];
			} else if (r[ind] < now) {
				tmp += now - r[ind];
				now = r[ind];
			}
		} else {
			while (u[tr[cr]] == 1) {
				cr++;
			}
			u[tr[cr]] = 1;
			int ind = tr[cr];
			if (now < l[ind]) {
				tmp += l[ind] - now;
				now = l[ind];
			} else if (r[ind] < now) {
				tmp += now - r[ind];
				now = r[ind];
			}
		}
	}
	tmp += abs(now);
	chmax(res, tmp); 
	put(res);
	return 0;
}

Measured memory_bytes: 6144