#include <bits/stdc++.h>
using namespace std;
constexpr int kUp = 0;
constexpr int kDown = 1;
long long max_weights(int N, int M, std::vector<int> X, std::vector<int> Y,
std::vector<int> W) {
vector<vector<pair<int, int>>> fishes(N);
for (int i = 0; i < M; ++i) {
fishes[X[i]].push_back(make_pair(Y[i], i));
}
long long largest = 0;
vector<pair<int, long long>> up, down;
vector<vector<long long>> dp(M, vector<long long>(2, LLONG_MIN / 2));
for (int x = 0; x < N; ++x) {
sort(fishes[x].begin(), fishes[x].end());
if (x > 0) {
long long max_down = 0;
for (int j = (int)fishes[x].size() - 1; j >= 0; --j) {
int y = fishes[x][j].first;
int i = fishes[x][j].second;
while (down.size() > 0 && down.back().first > y) {
max_down = max(max_down, down.back().second);
down.pop_back();
}
long long &ret = dp[i][kDown];
ret = largest + W[i];
ret = max(ret, max_down + W[i]);
if (j + 1 < static_cast<int>(fishes[x].size())) {
ret = max(ret, dp[fishes[x][j + 1].second][kDown] + W[i]);
}
}
}
if (x >= 1) {
for (auto [y, i] : fishes[x - 1]) {
largest = max(largest, dp[i][kDown]);
}
}
long long max_up = 0;
for (int j = 0; j < static_cast<int>(fishes[x].size()); ++j) {
int y = fishes[x][j].first;
int i = fishes[x][j].second;
while (up.size() > 0 && up.back().first < y) {
max_up = max(max_up, up.back().second);
up.pop_back();
}
long long &ret = dp[i][kUp];
ret = largest + W[i];
ret = max(ret, max_up + W[i]);
if (j > 0) {
ret = max(ret, dp[fishes[x][j - 1].second][kUp] + W[i]);
}
}
if (x >= 1) {
for (auto [y, i] : fishes[x - 1]) {
largest = max(largest, dp[i][kUp]);
}
}
down.clear();
for (int j = 0; j < static_cast<int>(fishes[x].size()); ++j) {
down.push_back(make_pair(fishes[x][j].first, dp[fishes[x][j].second][kDown]));
}
up.clear();
for (int j = static_cast<int>(fishes[x].size()) - 1; j >= 0; --j) {
up.push_back(make_pair(fishes[x][j].first, dp[fishes[x][j].second][kUp]));
}
}
long long answer = 0;
for (int i = 0; i < M; ++i) {
answer = max(answer, dp[i][kDown]);
if (X[i] + 1 < N) {
answer = max(answer, dp[i][kUp]);
}
}
return answer;
}
