#include <iostream>
#include <set>
#include <vector>
#include <map>
#include <unordered_map>
#include <valarray>
#include <queue>

using namespace std;

using ll = long long;
#define umap unordered_map
#define uset unordered_set
#define int ll

namespace std {
    template<typename T, typename U>
    struct hash<pair<T, U>> {
        size_t operator()(const pair<T, U> &a) const {
            return std::hash<T>()(a.first) ^ (std::hash<U>()(a.second) << 10);
        }
    };
}

signed main() {
    int cunt = 0;
    cin >> cunt;
    pair<ll, ll> c;
    vector<pair<ll, ll>> nodes;
    for (int i = 0; i < cunt; ++i) {
        cin >> c.first;
        cin >> c.second;
        nodes.push_back(c);
    }
    std::sort(nodes.begin(), nodes.end());
    priority_queue<pair<ll, pair<size_t, size_t>>> q;
    auto current = nodes[0];
    size_t index = 0;
    while (nodes[index] == current) {
        q.emplace(0, pair<size_t, size_t>{index, 1});
        index++;
    }
    while (!q.empty()) {
        auto kekel = q.top();
        q.pop();
        if(kekel.second.second == nodes.size()-1){
            cout << kekel.first << endl;
            break;
        }
        size_t next = kekel.second.first + 1;
        size_t nextest = kekel.second.first + 1;
        while (nextest < nodes.size() && nodes[next].first == nodes[nextest].first) {
            q.emplace(
                    kekel.first + abs(nodes[nextest].second - nodes[kekel.second.first].second) +
                    abs(nodes[nextest].first - nodes[kekel.second.first].first),
                    pair<size_t, size_t>{next, kekel.second.first + 1});
            nextest++;
        }
    }
    return 0;
}