#include "fish.h"
#include <bits/stdc++.h>
#define int long long
using namespace std;
vector<vector<int>> a;
vector<vector<int>> fsh;
vector<vector<int>> prefx;
vector<vector<vector<int>>> memo;
int N,M;
int dp(int x, int last, int lastlast){
if(memo[x][last][lastlast]!=-1) return memo[x][last][lastlast];
if(x==N) return memo[x][last][lastlast]=0;
memo[x][last][lastlast] = 0;
for (auto i:fsh[x])
{
int c=dp(x+1, i, last);
if(x>0) c+=max(0LL,prefx[x-1][max(i,lastlast)]-prefx[x-1][last]);
if(x==N-1) c+=max(0LL,prefx[x][last]-prefx[x][i]);
memo[x][last][lastlast]=max(c, memo[x][last][lastlast]);
}
return memo[x][last][lastlast];
}
long long max_weights(signed n, signed m, std::vector<signed> X, std::vector<signed> Y, std::vector<signed> W) {
N=n; M=m;
a.resize(N, vector<int>(N,0));
fsh.resize(N+1, vector<int>(1,0));
prefx.resize(N, vector<int>(N+1,0)); //y+1
memo.resize(N+1, vector<vector<int>>(N+1, vector<int>(N+1,-1)));
for (int i = 0; i < M; i++){
a[X[i]][Y[i]] = W[i];
fsh[X[i]+1].push_back(Y[i]+1);
if(X[i]>0) fsh[X[i]-1].push_back(Y[i]+1);
}
for (int x = 0; x < N; x++)
{
for (int y = 0; y < N; y++)
{
prefx[x][y+1]=a[x][y]+prefx[x][y];
}
}
int p=dp(0,0,0);
return p;
}
