#pragma GCC optimize("O3")
#include "fish.h"
#include <bits/stdc++.h>
#define ll long long
#define endl '\n'
using namespace std;
const ll INF = 3e14 + 4;
ll max_weights(int N, int M, vector<int> X, vector<int> Y, vector<int> W) {
int flag = 0;
for(int i = 0; i < M; i++){
if(Y[i] != 0){
flag = 1;
}
}
if(!flag){
ll dp[N][2], a[N];
memset(dp, 0, sizeof(dp)); memset(a, 0, sizeof(a));
for(int i = 0; i < M; i++) a[X[i]] += W[i];
dp[1][0] = a[1];
dp[1][1] = a[0];
for(int i = 2; i < N; i++){
dp[i][0] = max(dp[i - 1][1] + a[i], dp[i - 1][0]);
dp[i][1] = max(max(dp[i - 2][0] + a[i - 1], dp[i - 1][1]), dp[i - 2][1] + a[i - 1]);
}
return max(dp[N - 1][0], dp[N - 1][1]);
}
ll ans[N + 1][2];
memset(ans, 0, sizeof(ans));
for(int i = 0; i < M; i++){
ans[Y[i] + 1][X[i]] = W[i];
}
for(int i = 1; i <= N; i++){
ans[i][0] += ans[i - 1][0];
ans[i][1] += ans[i - 1][1];
}
ll res = 0;
for (int i = 1; i <= N; i++)
{
res = max(res, ans[i - 1][0] + (ans[N][1] - ans[i - 1][1]));
}
return res;
}
