#include "fish.h"
#include <bits/stdc++.h>
#include <vector>
using namespace std;
long long zero[3030], full[3030], dp[2][3030][3030], grid[3030][3030], sum[3030][3030];
long long max_weights(int N, int M, std::vector<int> X, std::vector<int> Y, std::vector<int> W) {
for (int i = 0; i < M; i++) {
X[i] += 1;
Y[i] += 1;
grid[X[i]][Y[i]] = W[i];
}
for (int i = 1; i <= N; i++) {
for (int j = 1; j <= N; j++) sum[i][j] = sum[i][j - 1] + grid[i][j];
}
for (int j = 1; j < N; j++) dp[0][0][j] = dp[1][0][j] = -1e18;
full[0] = -1e18;
for (int i = 2; i <= N + 1; i++) {
for (int k = 1; k < N; k++) zero[i] = max(zero[i], dp[1][i - 1][k] + sum[i][k]);
zero[i] = max(zero[i], zero[i - 1]);
zero[i] = max(zero[i], full[i - 1] + sum[i][N]);
for (int k = 1; k < N; k++) full[i] = max(full[i], dp[0][i - 1][k] + sum[i - 1][N] - sum[i - 1][k]);
full[i] = max(full[i], full[i - 1]);
full[i] = max(full[i], zero[i - 2] + sum[i - 1][N]);
full[i] = max(full[i], full[i - 2] + sum[i - 1][N]);
for (int l = 1; l < N; l++) full[i] = max(full[i], dp[1][i - 2][l] + sum[i - 1][N]);
long long val0 = 0, val1 = 0;
for (int k = 1; k < N; k++) {
val0 = max(val0, dp[0][i - 1][k] - sum[i - 1][k]);
val1 = max(val1, dp[1][i - 1][k] + sum[i][k]);
}
for (int j = 1; j < N; j++) {
dp[0][i][j] = max(dp[0][i][j], val0 + sum[i - 1][j]);
dp[1][i][j] = max(dp[1][i][j], val1 - sum[i][j]);
dp[1][i][j] = max(dp[1][i][j], full[i - 1] + sum[i][N] - sum[i][j]);
dp[0][i][j] = max(dp[0][i][j], zero[i - 2] + sum[i - 1][j]);
dp[0][i][j] = max(dp[0][i][j], full[i - 2] + sum[i - 1][N]);
}
long long val2 = 0;
for (int j = 1; j < N; j++) {
val2 = max(val2, dp[1][i - 2][j]);
dp[0][i][j] = max(dp[0][i][j], val2 + sum[i - 1][j]);
}
long long val3 = 0;
for (int j = N - 1; j >= 1; j--) {
val3 = max(val3, dp[1][i - 2][j] + sum[i - 1][j]);
dp[0][i][j] = max(dp[0][i][j], val3);
}
}
long long res = 0;
res = zero[N + 1];
return res;
}
