#include "fish.h"
#include <bits/stdc++.h>
using namespace std;
int n;
vector<vector<long long>> nxt;
vector<vector<long long>> pre;
vector<vector<vector<long long>>> dp;
vector<vector<pair<int, int>>> in_col;
long long max_weights(int N, int M, vector<int> X, vector<int> Y, vector<int> W) {
n = N;
in_col.resize(N);
for (int i = 0; i < M; ++i) {
in_col[X[i]].push_back({Y[i], W[i]});
}
for (int i = 0; i < N; ++i) {
sort(in_col[i].begin(), in_col[i].end());
in_col[i].push_back({N, 0});
}
pre.resize(N);
for (int col = 1; col < N; ++col) {
pre[col].resize(in_col[col].size());
for (int i = 0; i < (int) in_col[col].size(); ++i) {
int ptr = 0;
long long sum = 0;
while (ptr < (int) in_col[col - 1].size() && in_col[col - 1][ptr].first < in_col[col][i].first) {
sum += in_col[col - 1][ptr].second;
ptr++;
}
pre[col][i] = sum;
}
}
nxt.resize(N);
for (int col = 0; col < N - 1; ++col) {
nxt[col].resize(in_col[col].size());
for (int i = 0; i < (int) in_col[col].size(); ++i) {//M tot
int ptr = 0;
long long sum = 0;
while (ptr < (int) in_col[col + 1].size() && in_col[col + 1][ptr].first < in_col[col][i].first) {
sum += in_col[col + 1][ptr].second;
ptr++;
}
nxt[col][i] = sum;
}
}
dp.resize(N + 1);
for (int i = 0; i < N + 1; ++i) {
dp[i].resize(2);
dp[i][0].assign(2, -1);
dp[i][1].assign(2, -1);
}
dp[0][0][0] = 0;
for (int col = 0; col < N; ++col) {
int sz = (int) in_col[col].size();
for (int f = 0; f < 2; ++f) {
for (int f2 = 0; f2 < 2; ++f2) {
if (dp[col][f][f2] == -1) {
continue;
}
if (f) {
long long s = 0;
for (int i = 0; i < sz; ++i) {
long long w = s;
if (col < N - 1) {
w += nxt[col][i];
}
dp[col + 1][1][0] = max(dp[col + 1][1][0], dp[col][f][f2] + w);
s -= in_col[col][i].second;
}
dp[col + 1][0][0] = max(dp[col + 1][0][0], dp[col][f][f2]);
} else {
long long s = 0;
for (int i = 0; i < sz; ++i) {
long long w = s;
if (f2) {
w += pre[col][i];
}
dp[col + 1][0][1] = max(dp[col + 1][0][1], dp[col][f][f2] + w);
s -= in_col[col][i].second;
}
s = 0;
if (col < N - 1) {
s = nxt[col][sz - 1];
}
if (f2) {
s += pre[col][sz - 1];
}
dp[col + 1][1][0] = max(dp[col + 1][1][0], dp[col][f][f2] + s);
}
}
}
}
long long ans = 0;
for (int f = 0; f < 2; ++f) {
for (int f2 = 0; f2 < 2; ++f2) {
ans = max(ans, dp[n][f][f2]);
}
}
return ans;
}
