#include <bits/stdc++.h>
using namespace std;// Hello world arsaoshe aneru nesi isods
const int mod = 1e9+7; const char nl = '\n'; typedef long long ll; const int N = 1e5 + 5 ;
#define ff first
#define ss second
void void_code () {
ll s; cin >> s ; ll n; cin >> n;
vector < pair < int , pair < int , int > > > vec ( n) ;
for ( int i =0 ; i < n; i ++ ) {
cin >> vec [ i ] . ff >> vec [ i ] . ss . ff >> vec [ i ] . ss . ss ;
}
ll ans = 0;
sort ( vec . rbegin () , vec . rend () ) ;
for ( int i = 0 ; i < n; i ++ ) {
while ( s - vec [ i ] . ss . ff >= 0 and vec [ i ] . ss . ss != 0 ) {
vec [ i ] . ss . ss -- ;
ans += vec [ i ] . ff ;
s -= vec [ i ] . ss . ff ;
}
}
cout << ans ;
}
signed main() {
ios_base::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);
int t = 1; //test
//~ cin >> t;
while (t--) void_code ();
return 0;
}
