// bdz.cpp : Defines the entry point for the console application.
//

#include<iostream>
#include<cmath>
#include<fstream>
using namespace std;

float stops[301];
double max_(int n) {
	double max = 0;
	for(int i=0;i<=n;i++) {
		if(stops[i] > max)
			max = stops[i];
	}
	return max;
}

int main() {
	ifstream in("bdz.in");
	ofstream out("bdz.out");
	int n,m;
	in>>n>>m;
	int from,to,p;
	for(int i=0;i<m;i++) {
		in>>p>>from>>to;
		for(int j=from;j<to;j++) {
			stops[j] += p;
		}
		stops[to] -= p;
	}
	out<<ceil(double (max_(n)/64.0))<<endl;
	return 0;
}