#include "fish.h"
#include <bits/stdc++.h>
//#include "grader.cpp"
using namespace std;
#define int long long
#define ld long double
#define show(x,y) cout << y << " " << #x << endl;
#define show2(x,y,i,j) cout << y << " " << #x << " " << j << " " << #i << endl;
#define show3(x,y,i,j,p,q) cout << y << " " << #x << " " << j << " " << #i << " " << q << " " << #p << endl;
#define show4(x,y) for(auto it:y) cout << it << " "; cout << #x << endl;
typedef pair<int,int>pii;
typedef pair<int,pii>pi2;
mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count());
long long max_weights(int32_t n, int32_t m, vector<int32_t>a, vector<int32_t>b, vector<int32_t>w){
vector<int>dis[n+5];
for(int x=0;x<m;x++){
a[x]++;
b[x]++;
dis[a[x]].push_back(b[x]-1);
dis[a[x]].push_back(b[x]);
dis[a[x]-1].push_back(b[x]);
dis[a[x]+1].push_back(b[x]);
}
for(int x=0;x<=n;x++){
dis[x].push_back(0);
dis[x].push_back(n);
}
vector<int>arr[n+5];
for(int x=0;x<=n;x++){
sort(dis[x].begin(),dis[x].end());
dis[x].resize(unique(dis[x].begin(),dis[x].end())-dis[x].begin());
//show4(dis[x],dis[x]);
arr[x]=vector<int>(dis[x].size()+5,0);
}
for(int x=0;x<m;x++){
int index=lower_bound(dis[a[x]].begin(),dis[a[x]].end(),b[x])-dis[a[x]].begin();
arr[a[x]][index]+=w[x];
}
vector<int>dp[2][n+5];
dp[0][0]=vector<int>(dis[0].size()+5,-1e15);
dp[1][0]=vector<int>(dis[0].size()+5,-1e15);
dp[0][0][0]=0;
for(int index=1;index<=n;index++){
dp[0][index]=vector<int>(dis[index].size()+5,-1e15);
dp[1][index]=vector<int>(dis[index].size()+5,-1e15);
//go up
int add=-1e15;
int add2=0;
int ptr=0;
int cur=0;
for(auto h:dis[index]){
while(ptr<(int)dis[index-1].size()&&dis[index-1][ptr]<=h){
add=max(add+arr[index-1][ptr],dp[0][index-1][ptr]);
add2+=arr[index-1][ptr];
ptr++;
}
dp[0][index][cur]=max(dp[0][index][cur],add);
if(h==n){
dp[1][index][cur]=max(dp[0][index][cur],dp[1][index][cur]);
if(index>2){
int target=lower_bound(dis[index-2].begin(),dis[index-2].end(),n)-dis[index-2].begin();
dp[1][index][cur]=max(dp[1][index][cur],add2+dp[0][index-2][target]);
}
}
cur++;
}
//go down
add=-1e15;
ptr=dis[index-1].size()-1;
for(int y=dis[index].size()-1;y>=0;y--){
int h=dis[index][y];
while(ptr>=0&&dis[index-1][ptr]>=h){
add=max(add,dp[1][index-1][ptr]);
ptr--;
}
dp[1][index][y]=max(dp[1][index][y],add);
add+=arr[index][y];
}
dp[0][index][0]=max(dp[1][index-1][0],dp[0][index][0]);
//show(index,index-1);
//show4(dis[index],dis[index]);
//show4(dp0,dp[0][index]);
//show4(dp1,dp[1][index]);
}
int maxi=0;
for(int x=0;x<=n;x++){
for(auto it:dp[0][x]) maxi=max(maxi,it);
for(auto it:dp[1][x]) maxi=max(maxi,it);
}
return maxi;
}
