// Om Namah Shivaya
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template<typename T> using Tree = tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define ff first
#define ss second
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define conts continue
#define sz(a) a.size()
#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)
template<typename T>
void amin(T &x, T y){
x = min(x,y);
}
template<typename T>
void amax(T &x, T y){
x = max(x,y);
}
#define debug(x) cout << #x << " = "; cout << x; cout << endl
const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = 1e9 + 5;
const ll inf2 = (ll)1e18 + 5;
#include "fish.h"
template<typename T>
struct segtree{
struct data{
ll a;
};
data d_neutral = {-inf2};
data merge(data &left, data &right){
data curr;
curr.a = max(left.a,right.a);
return curr;
}
void modify(int i, T v){
tr[i].a = v;
}
int n;
vector<data> tr;
segtree(int n_){
n = n_;
tr.assign(2*n+5,d_neutral);
}
void pupd(int i, T v){
modify(i+n,v);
for(i = (i+n)>>1; i; i >>= 1){
tr[i] = merge(tr[i<<1],tr[i<<1|1]);
}
}
data query(int l, int r){
data res = d_neutral;
for(l += n, r += n; l <= r; l >>= 1, r >>= 1){
if(l & 1){
res = merge(res,tr[l++]);
}
if(!(r & 1)){
res = merge(res,tr[r--]);
}
}
return res;
}
};
vector<pll> here[N];
ll n;
vector<vector<ll>> dp[N];
long long max_weights(int n_, int m, std::vector<int> X, std::vector<int> Y,
std::vector<int> W) {
n = n_;
rep(i,m){
here[X[i]].pb({Y[i],W[i]});
}
rep(i,n){
sort(all(here[i]));
}
vector<ll> best(n);
segtree<ll> st(n+5);
rep(i,n){
auto &a = here[i];
ll siz = sz(a);
auto &dp1 = dp[i];
dp1 = vector<vector<ll>>(siz,vector<ll>(2));
ll mx = 0;
if(i >= 2){
mx = best[i-2];
}
ll prev_mx = -inf2;
if(i){
auto &b = here[i-1];
rep(j,sz(b)){
amax(prev_mx,dp[i-1][j][0]);
}
}
if(i){
auto &b = here[i-1];
rep(j,sz(b)){
st.pupd(b[j].ff,dp[i-1][j][1]);
}
}
rep(j,siz){
if(j){
dp1[j][1] = dp1[j-1][1]+a[j].ss;
}
else{
dp1[j][1] = mx+a[j].ss;
}
amax(dp1[j][1],prev_mx+a[j].ss);
if(i){
ll best = st.query(0,a[j].ff-1).a;
amax(dp1[j][1],best+a[j].ss);
// auto &b = here[i-1];
// rep(j2,sz(b)){
// if(a[j].ff > b[j2].ff){
// amax(dp1[j][1],dp[i-1][j2][1]+a[j].ss);
// }
// }
}
}
if(i){
auto &b = here[i-1];
rep(j,sz(b)){
st.pupd(b[j].ff,-inf2);
}
}
if(i){
auto &b = here[i-1];
rep(j,sz(b)){
st.pupd(b[j].ff,dp[i-1][j][0]);
}
}
if(i){
rev(j,siz-1,0){
if(j+1 < siz){
dp1[j][0] = dp1[j+1][0]+a[j].ss;
}
else{
dp1[j][0] = mx+a[j].ss;
}
ll best = st.query(a[j].ff+1,n).a;
amax(dp1[j][0],best+a[j].ss);
// auto &b = here[i-1];
// rep(j2,sz(b)){
// if(a[j].ff < b[j2].ff){
// amax(dp1[j][0],dp[i-1][j2][0]+a[j].ss);
// }
// }
}
}
else{
rep(j,siz){
dp1[j][0] = -inf2;
}
}
if(i){
auto &b = here[i-1];
rep(j,sz(b)){
st.pupd(b[j].ff,-inf2);
}
}
if(i){
best[i] = best[i-1];
}
rep(j,siz){
rep(k,2){
amax(best[i],dp1[j][k]);
}
}
}
ll ans = 0;
rep(i,n){
rep(j,sz(here[i])){
rep(k,2){
if(i == n-1 and k == 1) conts;
amax(ans,dp[i][j][k]);
}
}
}
return ans;
}
