#include <bits/stdc++.h>
using namespace std;
const int MAX = 2015;
const int MOD = 1000000000;
const int dx[] = {0, 0, 1, -1};
const int dy[] = {1, -1, 0, 0};
vector<int> adj[MAX];
bool adjacent(int x1, int y1, int x2, int y2){
for(int i = 0; i < 4; i++){
int nx = x1 + dx[i], ny = y1 + dy[i];
if(nx == x2 && ny == y2) return true;
}
return false;
}
int DistanceSum(int N, int X[], int Y[]) {
int resp = 0;
for(int i = 0; i < N; i++)
for(int j = i + 1; j < N; j++)
if(adjacent(X[i], Y[i], X[j], Y[j])){
adj[i].emplace_back(j);
adj[j].emplace_back(i);
}
for(int i = 0; i < N; i++){
queue<int> q; vector<int> dist(N, -1);
q.push(i); dist[i] = 0;
while(q.size()){
int u = q.front(); q.pop();
for(auto v : adj[u]){
if(dist[v] != -1) continue;
dist[v] = dist[u] + 1;
q.push(v);
}
}
for(int j = 0; j < N; j++) resp += dist[j];
resp %= MOD;
}
return resp >> 1;
}
