#include <bits/stdc++.h>
using namespace std;
#define int long long
#define all(a) (a).begin(), (a).end()
#define pb push_back
#define mk make_pair
#define pii pair<int, int>
#define ff first
#define ss second
#define inp_v(vec) for (auto &i : vec) cin >> i;
#define prt_v(vec) for (auto i : vec) cout << i << endl;
#define MS(x) memset(x, 0, sizeof(x))
#define gcd(a,b) __gcd(a, b);
#define lcm(a,b) (a*(b/gcd(a,b)))
#define lb lower_bound
#define ub upper_bound
bool chmin(int &a, int b){return b<a?a=b, true:false;}
bool chmax(int &a, int b){return b>a?a=b, true:false;}
bool comp(const pair<int, int>&a, const pair<int, int>&b){
return a.first>b.first;
}
signed main(){
ios_base::sync_with_stdio(false); cin.tie(0);
int N, M;cin>>N>>M;
int dp[N+1][N+1];
vector<vector<pair<int,int>>>simp(N+5), v(N+5);
for(int i=0;i<M;i++){
int a, b, c;
cin>>a>>b>>c;
simp[b].push_back({a, c});
}
for(int i=1;i<=N;i++){
if(!simp[i].size())continue;
sort(simp[i].begin(), simp[i].end(), comp);
int cost=0, val=0;
bool stat=true;
v[i].push_back({0, 0});
for(auto j:simp[i]){
if(!stat)break;
for(int k=0;k<j.second;k++){
cost+=i;
val+=j.first;
// cout<<cost<<" "<<val<<endl;
if(cost>N){
stat=false;
break;
}
v[i].push_back({val, cost});
}
}
}
memset(dp, 0, sizeof(dp));
for(int i=1;i<=N;i++){
if(v[i].size()){
for(auto j:v[i]){
for(int k=0;k<=N;k++){
if(k>=j.second){
dp[i][k]=max(dp[i-1][k], dp[i-1][k-j.second]+j.first);
}
else{
dp[i][k]=max(dp[i][k], dp[i-1][k]);
}
}
}
}
else{
for(int k=0 ;k<=N;k++){
dp[i][k]=dp[i-1][k];
}
}
}
cout<<dp[N][N]<<endl;
return 0;
}
