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 */
#pragma GCC target("sse4,tune=native")
#pragma GCC optimize("O3","unroll-loops")
#include <iostream>
#include <complex>
#include <vector>
#include <string>
#include <algorithm>
#include <cstdio>
#include <numeric>
#include <cstring>
#include <ctime>
#include <cstdlib>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <list>
#include <cmath>
#include <bitset>
#include <cassert>
#include <queue>
#include <stack>
#include <deque>
    
     
using namespace std;
template<typename T1, typename T2>inline void chkmin(T1 &x, T2 y) { if (x > y) x = y; }
template<typename T1, typename T2>inline void chkmax(T1 &x, T2 y) { if (x < y) x = y; } 
template<typename T, typename U> inline ostream &operator<< (ostream &_out, const pair<T, U> &_p) { _out << _p.first << ' ' << _p.second; return _out; }
template<typename T, typename U> inline istream &operator>> (istream &_in, pair<T, U> &_p) { _in >> _p.first >> _p.second; return _in; }
template<typename T> inline ostream &operator<< (ostream &_out, const vector<T> &_v) { if (_v.empty()) { return _out; } _out << _v.front(); for (auto _it = ++_v.begin(); _it != _v.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T> inline istream &operator>> (istream &_in, vector<T> &_v) { for (auto &_i : _v) { _in >> _i; } return _in; }
template<typename T> inline ostream &operator<< (ostream &_out, const set<T> &_s) { if (_s.empty()) { return _out; } _out << *_s.begin(); for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T> inline ostream &operator<< (ostream &_out, const multiset<T> &_s) { if (_s.empty()) { return _out; } _out << *_s.begin(); for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T> inline ostream &operator<< (ostream &_out, const unordered_set<T> &_s) { if (_s.empty()) { return _out; } _out << *_s.begin(); for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T> inline ostream &operator<< (ostream &_out, const unordered_multiset<T> &_s) { if (_s.empty()) { return _out; } _out << *_s.begin(); for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T, typename U> inline ostream &operator<< (ostream &_out, const map<T, U> &_m) { if (_m.empty()) { return _out; } _out << '(' << _m.begin()->first << ": " << _m.begin()->second << ')'; for (auto _it = ++_m.begin(); _it != _m.end(); ++_it) { _out << ", (" << _it->first << ": " << _it->second << ')'; } return _out; }
template<typename T, typename U> inline ostream &operator<< (ostream &_out, const unordered_map<T, U> &_m) { if (_m.empty()) { return _out; } _out << '(' << _m.begin()->first << ": " << _m.begin()->second << ')'; for (auto _it = ++_m.begin(); _it != _m.end(); ++_it) { _out << ", (" << _it->first << ": " << _it->second << ')'; } return _out; }
#define sz(c) (int)(c).size()
#define all(c) (c).begin(), (c).end()
#define rall(c) (c).rbegin(), (c).rend()
#define left left228
#define right right228
#define next next228
#define rank rank228
#define prev prev228
#define y1 y1228                                                         
#define read(FILENAME) freopen((FILENAME + ".in").c_str(), "r", stdin)
#define write(FILENAME) freopen((FILENAME + ".out").c_str(), "w", stdout)
#define files(FILENAME) read(FILENAME), write(FILENAME)
#define pb push_back
const string FILENAME = "input";
const int MAXN = 300228;


int n;
int l[MAXN], r[MAXN];


long long get() {
	set<pair<int, int> > s, s1;
	for (int i = 0; i < n; i++) {
		s.insert({r[i], i});
		s1.insert({l[i], i});
	}
	int cur = 0;
	long long res = 0;
	for (int i = 0; i < n; i++) {
		if (i % 2 == 0) {
			pair<int, int> f = *s.begin();
			s.erase(f);
			s1.erase({l[f.second], f.second});
			if (l[f.second] <= cur && cur <= f.first) {
				continue;
			}
			if (l[f.second] > cur) {
				res += l[f.second] - cur;
				cur = l[f.second];
			} else {
				res += cur - r[f.second];
				cur = r[f.second];
			}
		} else {
			pair<int, int> f = *s1.rbegin();
			s1.erase(f);
			s.erase({r[f.second], f.second});
			if (r[f.second] >= cur && cur >= f.first) {
				continue;
			}
			if (r[f.second] < cur) {
				res += cur - r[f.second];
				cur = r[f.second];
			} else {
				res += l[f.second] - cur;
				cur = l[f.second];
			}
		}
	}
	res += abs(cur);
	return res;
}


int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	//read(FILENAME);
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> l[i] >> r[i];
	}
	long long ans = get();
	for (int i = 0; i < n; i++) {
		l[i] *= -1;
		r[i] *= -1;
		swap(l[i], r[i]);
	}
	chkmax(ans, get());
	cout << ans << '\n';
	return 0;
}


Measured memory_bytes: 12416