#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <string>
#include <algorithm>
#include <iostream>
using namespace std;

struct P {
    int x, y;
    P(int X = 0, int Y = 0) : x(X), y(Y) {}
} p[4010];

struct R {
    P a, b;
    R(P A = P(), P B = P()) : a(A), b(B) {}
    int len() {
        return abs(a.x - b.x) + abs(a.y - b.y);
    }
    bool isHoriz() {
        return a.y == b.y;
    }
    bool between(int x, int a, int b) {
        return ((a <= x && x <= b) || (a >= x && x >= b));
    }
    pair<bool, P> intersects(R &r) {
        if (isHoriz() == r.isHoriz())
            return make_pair(0, P());
        if (isHoriz()) {
            if (between(r.a.x, a.x, b.x) && between(a.y, r.a.y, r.b.y))
                return make_pair(1, P(r.a.x, a.y));
        } else {
            if (between(r.a.y, a.y, b.y) && between(a.x, r.a.x, r.b.x))
                return make_pair(1, P(a.x, r.a.y));
        }
        return make_pair(0, P());
    }
} r[4010];

int n, l[4000];
vector<int> ans;

int sLen(int ra, int rb) {
    return l[rb] - (ra ? l[ra - 1] : 0);
}

int main() {
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    scanf("%d", &n);
    for (int i = 0; i < n; i++)
        scanf("%d%d", &p[i].x, &p[i].y);
    for (int i = 0; i < n - 1; i++) {
        r[i] = R(p[i], p[i + 1]);
        l[i] = r[i].len() + (i ? l[i - 1] : 0);
        for (int j = 0; j < i - 1; j++) {
            pair <bool, P> inter = r[i].intersects(r[j]);
            if (inter.first)
                ans.push_back(sLen(j + 1, i - 1) + R(r[i].a, inter.second).len() + R(inter.second, r[j].b).len());
        }
    }
    ans.push_back(l[n - 2]);
    printf("%d", *min_element(ans.begin(), ans.end()));
    return 0;
}