#include <bits/stdc++.h>
#include <cmath>
#include <chrono>
#include <numeric>
using namespace std;
#define fasterio ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0);
#define endl "\n"
#define ll long long
#define testcase int t; cin>>t; for(int i=0;i<t;i++)
#define int long long
//#define double long double
#define pb push_back
#define dbugvec(v) for(int i=0;i<v.size();i++){ cout << v[i] << " ";}cout << endl;
#define dbugarr(arr) for(int i=0;i<(sizeof(arr)/sizeof(arr[0]));i++){ cout << arr[i] << " ";}cout << endl;
#define dbug2dvec(v) for(int i=0;i<v.size();i++){for(int j=0;j<v[i].size();j++){cout << v[i][j] << " ";}cout << endl;}
ll mod= 1e9+7;
//ll N = 252000;
ll inf = 1e18;
double e=2.718281828459045235360;
//FUNCTIONS
ll inv(ll a, ll b = mod) { return 1 < a ? b - inv(b % a, a) * b / a : 1; }
// bool cmp(pair<int,int> a,pair<int,int> b){ return a.second>b.second;}
bool cmp(vector<int> alpha, vector<int> beta)
{
return (alpha[0]/alpha[1])>(beta[0]/beta[1]);
}
int binpow(int a, int b, int m) {
a %= m;
int res = 1;
while (b > 0) {
if (b & 1)
res = res * a % m;
a = a * a % m;
b >>= 1;
}
return res;
}
void dij(vector<int>&dist,vector<vector<pair<int,int>>> &adj,int node)
{
vector<int> vis(dist.size(),0);
priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>> pq;
pq.push({0,node});
while(pq.size()!=0)
{
int wt=pq.top().first;
int n=pq.top().second;
pq.pop();
if(vis[n]==1) continue;
vis[n]=1;
dist[n]=wt;
for(int i=0;i<adj[n].size();i++)
{
if(dist[adj[n][i].first]>wt+adj[n][i].second)
pq.push({wt+adj[n][i].second,adj[n][i].first});
}
}
}
int find_parent(int node,vector<int>&parent)
{
if(parent[node]==node) return node;
else
{
int alpha = find_parent(parent[node],parent);
parent[node] = alpha;
return alpha;
}
}
int dsu(vector<int>&size, vector<int>&parent, int node1,int node2)
{
if(find_parent(node1,parent)==find_parent(node2,parent)) return 0;
int alpha = find_parent(node1,parent);
int beta = find_parent(node2,parent);
if(size[alpha]==size[beta])
{
size[beta]+=size[alpha];
parent[alpha] = beta;
}
else
{
if(size[alpha]>size[beta])
{
size[alpha]+=size[beta];
parent[beta] = alpha;
}
else
{
size[beta]+=size[alpha];
parent[alpha] = beta;
}
}
return 1;
}
int dfs(vector<vector<int>>&adj,vector<int>&cyc,int node,int parent,vector<int> &vis)
{
vis[node]=1;
int alpha =0;
for(int i=0;i<adj[node].size();i++)
{
if(adj[node][i]==parent) continue;
else
{
if(vis[adj[node][i]]==1){cyc[node]=1; alpha = 1; cout<<node<<endl;}
else
alpha += dfs(adj,cyc,adj[node][i],node,vis);
}
}
if(alpha>=1) {cyc[node]=1;return 1;}
else return 0;
}
signed main()
{
fasterio
#ifndef ONLINE_JUDGE
freopen("error.txt", "w", stderr);
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
int s,n;
cin>>s>>n;
vector<vector<int>> v(n);
for(int i=0;i<n;i++)
{
int a,b,c;
cin>>a>>b>>c;
v[i].push_back(a);
v[i].push_back(b);
v[i].push_back(c);
}
sort(v.begin(), v.end(),cmp);
// for(int i=0;i<n;i++) cout<<v[i][0]<<endl;
int wt =0;
int profit = 0;
for(int i=0;i<n;i++)
{
int alpha = (s-wt)/v[i][1];
int beta = v[i][2];
wt+= min(alpha,beta)*v[i][1];
profit+= min(alpha,beta)*v[i][0];
}
cout<<profit<<endl;
}
