#include <bits/stdc++.h>
#define pb push_back
#define f first
#define sc second
using namespace std;
typedef long long int ll;
typedef string str;
ll max_weights(int n, int m, vector<int> X, vector<int> Y, vector<int> W){
vector<vector<ll>> v(n, vector<ll>(n+1, 0));
for(int i = 0; i < m; i++) v[X[i]][Y[i]+1]+=W[i];
vector<vector<ll>> dp_up(n, vector<ll>(n+1, 0)), dp_down = dp_up;
for(int i = n-1; i >= 0; i--) for(int j = 0; j <= n; j++){
if(i == n-1){
dp_down[i][j] = 0;
dp_up[i][j] = 0;
continue;
}
ll s = 0;
for(int k = j; k <= n; k++){
if(k > j) s+=v[i][k];
dp_up[i][j] = max(dp_up[i][j], s+dp_up[i+1][k]);
}
s = 0;
for(int k = j; k >= 0; k--){
if(k < j) s+=v[i+1][k+1];
dp_down[i][j] = max(dp_down[i][j], s+dp_down[i+1][k]);
}
s = 0;
for(int k = j+1; k <= n; k++) s+=v[i][k];
dp_up[i][j] = max(dp_up[i][j], s+dp_down[i+1][n]);
if(i+2 < n){
s = 0;
for(int k = 0; k <= j; k++) s+=v[i+1][k];
for(int k = 0; k <= n; k++){
if(k > j) s+=v[i+1][k];
dp_down[i][j] = max(dp_down[i][j], s+dp_up[i+2][k]);
}
dp_down[i][j] = max(dp_down[i][j], s+dp_down[i+2][n]);
}
}
return max(*max_element(dp_up[0].begin(), dp_up[0].end()), *max_element(dp_down[0].begin(), dp_down[0].end()));
}
