#include "fish.h"
#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define sz(a) (int)a.size()
#define all(a) begin(a),end(a)
using ll = long long;
using vi = vector<int>;
const int mxN = (int)1e5+10;
const ll LINF = (ll)2e18;
int n, m;
struct Fish{
	int x, y, w;
};
vector<Fish> fishes;
ll dp[mxN][2];
ll W[mxN];

ll max_weights(int N, int M, vi _X, vi _Y, vi _W) {
	n = N, m = M; 
	for(int i = 0; i < m; i++) 
		fishes.pb({_X[i]+1,_Y[i],_W[i]});
	sort(all(fishes),[&](Fish a, Fish b){
		if(a.x!=b.x) return a.x<b.x;
		return a.y<b.y;
	});
	memset(W,0,sizeof(W));
	for(auto [x,y,w] : fishes){
		W[x]=w;
	}
	for(int i = 0; i <= n+2; i++)
		for(int j = 0; j < 2; j++)
			dp[i][j]=-LINF;
	dp[0][0] = 0;
	for(int i = 1; i <= n+1; i++){
		dp[i][0] = max(dp[i-1][0],dp[i-1][1]+W[i]);
		if(i!=n+1) dp[i][1] = max(dp[i-1][0]+W[i-1],dp[i-1][1]);
	}
	return dp[n+1][0];
}