/*
 *  Copyright (c) 2015, Andrew Chen <llkiwi2006@gmail.com>
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are met:
 *
 *  1. Redistributions of source code must retain the above copyright notice,
 *  this list of conditions and the following disclaimer.
 *
 *  2. Redistributions in binary form must reproduce the above copyright notice,
 *  this list of conditions and the following disclaimer in the documentation
 *  and/or other materials provided with the distribution.
 *
 *  3. Neither the name of the copyright holder nor the names of its
 *  contributors may be used to endorse or promote products derived from this
 *  software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *  POSSIBILITY OF SUCH DAMAGE.
 */

#include <cstdio>
#include <cstring>
#include <algorithm>

#include <vector>

using namespace std;

int total_t; // `T`

struct item {
    int t, a, b;
    item(int _t, int _a, int _b) : t(_t), a(_a), b(_b) {}
};

bool cmp(const item& a, const item& b) {
    // sort according descending to `(b / t)`
    return ((double) a.b / a.t) > ((double) b.b / b.t);
}

long long f1[5001];
long long f2[5001];

int main() {
    int n;
    vector<item> items_pos;
    vector<item> items_neg;
    scanf("%d%d", &total_t, &n);
    for (int i = 0; i < n; i++) {
        int t, a, b;
        scanf("%d%d%d", &t, &a, &b);
        if (b >= 0) items_pos.push_back(item(t, a, b));
        else items_neg.push_back(item(t, a, b));
    }

    sort(items_pos.begin(), items_pos.end(), cmp);
    sort(items_neg.begin(), items_neg.end(), cmp);

    memset(f1, 0, sizeof(f1));
    memset(f2, 0, sizeof(f2));

    for (unsigned int i = 0; i < items_pos.size(); i++) {
        for (unsigned int j = 0; j <= total_t; j++) {
            if (j + items_pos[i].t <= total_t) {
                int value = items_pos[i].a + (j + items_pos[i].t) * items_pos[i].b;
                f1[j] = max(f1[j], f1[j + items_pos[i].t] + value);
            }
        }
    }
    for (int i = total_t - 1; i >= 0; i--) f1[i] = max(f1[i], f1[i + 1]);

    for (int i = items_neg.size() - 1; i >= 0; i--) {
        for (unsigned int j = 0; j <= total_t; j++) {
            if (j + items_neg[i].t <= total_t) {
                int value = items_neg[i].a + (total_t - j) * items_neg[i].b;
                f2[j] = max(f2[j], f2[j + items_neg[i].t] + value);
            }
        }
    }
    for (int i = total_t - 1; i >= 0; i--) f2[i] = max(f2[i], f2[i + 1]);

    long long the_max = 0;
    for (int j = 0; j <= total_t; j++) the_max = max(the_max, f1[j] + f2[total_t - j]);
    printf("%lld\n", the_max);
}