#include <cmath>
#include <cstring>
#include <ctime>
#include <iostream>
#include <algorithm>
#include <set>
#include <vector>
#include <sstream>
#include <typeinfo>
#include <fstream>
#include <map>

using namespace std;
int dx[]={1,-1,0,0};
int dy[]={0, 0,1,-1};
const int N=1010;

vector<int> x,y,finalPoints;
set< pair<int,int> > grid;
int k;

void blockInGrid() {
        int n=x.size();
        for(int i=0;i<n;i++) {
            auto t = make_pair(x[i],y[i]);
            grid.insert(t);
        }
}
void dfs(int x,int y,int t) {
    auto cur=make_pair(x,y);
    if(grid.count(cur)) {
        return ;
    }
    grid.insert(cur);
    if(t==k) {
        finalPoints.push_back(x);
        return;
    }

    for(int i=0;i<4;i++) {
        int nx=x+dx[i];
        int ny=y+dy[i];
        dfs(nx,ny,t+1);
    }
}

class TheGridDivTwo {
    public:
    int find(vector<int> _x, vector<int> _y, int _k) {
        x=_x;
        y=_y;
        k=_k;
        grid.clear();
        finalPoints.clear();
        blockInGrid();
        dfs(0,0,0);
        int res=0;
        for(int i : finalPoints) {
            res=max(res,i);
        }

        return res;
    }
};