猴子挖花生

#include <iostream>
#include <vector>
#include <cmath>

using namespace std;

int main()
{
    int n, i, sum = 0, cur_x = 0, cur_y = 0;
    cin >> n;
    vector <int> x;
    vector <int> y;
    for(i = 0; i < n; ++i) {
        int pn_x, pn_y;
        cin >> pn_x >> pn_y;
        x.push_back(pn_x);
        y.push_back(pn_y);
    }
    for(int j = 0; j < n; ++j) {
        sum += abs(x[j] - cur_x);
        sum += abs(y[j] - cur_y);
        cur_x = x[j];
        cur_y = y[j];
    }
    sum += abs(cur_x - 0);
    sum += abs(cur_y - 0);
    cout << sum << endl;
    return 0;
}