#define _CRT_SECURE_NO_DEPRECATE
#include <iostream>
#include <string>
#include <vector>
#include <sstream>
#include <queue>
#include <algorithm>
#include <iomanip>
#include <map>
#include <set>
#include <math.h>
#include <stack>
#include <deque>
#include <numeric>
#include <cstring>
#include <cstdio>
#include <ctime>
#include <cstdlib>
#include <bitset>

#define all(v) v.begin(),v.end()
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
const ld epsylon = 1e-9;
typedef unsigned int ui;
//inline long double get_time(){   
//	return (long double)clock()/CLOCKS_PER_SEC;
//};
//ld start_time,end_time;

int zad[120];

int main()
{
	freopen("bdz.in","r",stdin);
	freopen("bdz.out","w",stdout);
	//start_time = get_time();
	//program
	int n, m;
	memset(zad, 0, sizeof(zad));
	scanf("%d %d", &n, &m);
	int t1, t2, t3;
	for (int i = 0; i < m; ++i)
	{
		scanf("%d %d %d", &t1, &t2, &t3);
		for (int j = t2; j < t3; ++j)
			zad[j] += t1;
	}
	int mm = 0;
	for (int i = 1; i <= n; ++i)
		mm = max(mm, zad[i]);
	printf("%d\n", mm%64==0?mm/64:mm/64+1);
	
	//end program
	//end_time=get_time()-start_time;
	return 0;
}