#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 <cstdlib>
#include <bitset>
#define mpair make_pair
#define all(v) v.begin(),v.end()
using namespace std;
typedef long long ll;
typedef long double ld;
const ld epsylon = 1e-9;
int main()
{
  freopen("bdz.in","r",stdin);
  freopen("bdz.out","w",stdout);
  int n,m;
  cin >> n >> m;
  vector<int> vals(n+1, 0);
  for (int i =0 ;i<m;++i) {
    int a,b,c;
    cin >> a >> b >> c;
    for (int i=b;i<c;++i){
      vals[i]+= a;
    }
  }
  int mval = 0;
  for (int i=0;i<=n;++i){
    mval = max(mval, (vals[i] + 63)/64);
  }
  cout << mval << endl;
  return 0;
}