#include <bits/stdc++.h>
#include "fish.h"
using namespace std;
using ll = long long;
int n, m;
ll max_weights(int N, int M, vector<int> X, vector<int> Y, vector<int> W) {
n = N, m = M;
int r = 0, c = 0;
for (int i = 0;i < m;i++) {
r = max(r, X[i] + 1);
c = max(c, Y[i] + 1);
}
c++;
r = min(n, r + 1);
vector<vector<int>> a(r + 1, vector<int>(c + 1, 0));
vector<vector<vector<ll>>> dp(2, vector<vector<ll>>(r + 1, vector<ll>(c + 1, 0ll)));
for (int i = 0;i < m;i++) {
a[X[i] + 1][Y[i] + 1] = W[i];
}
ll mx;
for (int i = 2;i <= r;i++) {
// (0)
mx = 0;
for (int j = 0;j <= c;j++) {
mx = max(mx + a[i - 1][j], dp[0][i - 1][j]);
dp[0][i][j] = mx;
}
if (i >= 3) { // i - 2
ll sum = 0;
mx = 0;
for (int j = 0;j <= c;j++) {
mx = max({ mx, dp[0][i - 2][j], dp[1][i - 2][j] });
sum += a[i - 1][j];
dp[0][i][j] = max(dp[0][i][j], mx + sum);
}
mx = 0;
for (int j = c;j >= 0;j--) {
mx = max({ mx, max(dp[0][i - 2][j], dp[1][i - 2][j]) + sum });
dp[0][i][j] = max(dp[0][i][j], mx);
sum -= a[i - 1][j];
}
}
// (1)
mx = 0;
for (int j = c;j >= 0;j--) {
dp[1][i][j] = mx;
mx = max({ mx + a[i][j], dp[0][i - 1][j], dp[1][i - 1][j] });
}
}
ll ans = 0;
for (int i = 1;i <= r;i++) {
for (int j = 0;j <= c;j++) {
ans = max({ ans, dp[0][i][j], dp[1][i][j] });
}
}
return ans;
}
