#include "fish.h"
#ifdef NYAOWO
#include "grader.cpp"
#endif
#include <bits/stdc++.h>
#define For(i, a, b) for(int i = a; i <= b; i++)
#define Forr(i, a, b) for(int i = a; i >= b; i--)
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define sz(x) ((int)x.size())
#define eb emplace_back
#define int LL
using namespace std;
using i32 = int32_t;
using LL = long long;
using pii = pair<int, int>;
inline void chmax(int &x, int val) { x = max(x, val); }
const int MAXN = 3000;
const int INF = 1e15;
int n, m;
int useful[MAXN + 10][MAXN + 10];
int pre[MAXN + 10][MAXN + 10];
int dp1[MAXN + 10][MAXN + 10];
int dp2[MAXN + 10][MAXN + 10];
long long max_weights(i32 N, i32 M, vector<i32> X, vector<i32> Y,
vector<i32> W) {
n = N;
m = M;
memset(pre, 0, sizeof(pre));
For(i, 0, m - 1) {
X[i]++; Y[i]++;
pre[X[i]][Y[i]] += W[i];
For(dx, -2, 2) For(dy, -2, 2) {
int nx = X[i] + dx;
int ny = Y[i] + dy;
if(nx < 0 || nx > n + 1 || ny < 0 || ny > n + 1) {
;
} else {
useful[nx][ny] = 1;
}
}
}
For(i, 1, n) For(j, 1, n) {
pre[i][j] += pre[i][j - 1];
}
For(i, 0, n + 1) For(j, 0, n + 1) {
dp1[i][j] = dp2[i][j] = -INF;
}
dp2[0][0] = 0;
For(i, 1, n + 1) {
int mx = -INF;
For(j, 1, n) {
chmax(mx, dp1[i - 1][j] - pre[i - 1][j]);
chmax(mx, dp2[i - 1][j] - pre[i - 1][j]);
dp1[i][j] = dp2[i - 1][0] + pre[i - 1][j];
if(useful[i][j]) {
chmax(dp1[i][j], mx + pre[i - 1][j]);
}
}
mx = -INF;
Forr(j, n, 0) {
chmax(mx, dp2[i - 1][j]);
dp2[i][j] = dp1[i - 1][j] + pre[i][j];
if(useful[i][j] || j == 0) {
chmax(dp2[i][j], mx + pre[i][j] - pre[i - 1][j]);
}
}
}
int ans = 0;
For(j, 0, n) chmax(ans, dp2[n + 1][j]);
return ans;
}
/*
5 4
0 2 5
1 1 2
4 4 1
3 3 3
8
*/
