#include<iostream>
#include<fstream>

using namespace std;
int b[1000];
int main()
{
  ifstream fin("bdz.in");
  int N, M, i;
  int p, q, j;
  fin>>N;
  fin>>M;
  for(i = 1; i < M+1; i++){
     fin>>j>>p>>q;
     do
     {
      b[p] = b[p] + j;
      p++;
     }
     while (p <q);
  }
  int max = b[1];
  for(i = 2; i< N+1; i++) if (b[i]>max) max = b[i];

  ofstream fout("bdz.out");
  if (max%64 == 0) fout<<max/64;
  else fout<<max/64 + 1;
  fout.close();
  return 0;
}