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#include <algorithm>
#include <iostream>
using namespace std;

const int maxN = 1e6 + 6;
const int maxM = 1e6 + 6;
const int base = 1 << 20;

int mask(int k) {
  // k = 1 yellow
  // k = 2 blue
  // k = 3 red
  return 1 << (k - 1);
}

int green_mask = 3;
int tree_cnt[2 * base][8];
int tree_collor[2 * base];

void collor_query(int qb, int qe, int k, int ib = 0, int ie = base, int id = 1) {
  if (qb <= ib && ie <= qe) {
    tree_collor[id] |= mask(k);
    return;
  }
  int mid = (ib + ie) / 2;
  if (qb < mid) collor_query(qb, qe, k, ib, mid, id * 2);
  if (qe > mid) collor_query(qb, qe, k, mid, ie, id * 2 + 1);
  for (int i = 0; i < 8; i++) {
    tree_cnt[id][i] = 0;
  }
  for (int i = 0; i < 8; i++) {
    tree_cnt[id][tree_collor[id * 2] | i] += tree_cnt[id * 2][i];
    tree_cnt[id][tree_collor[id * 2 + 1] | i] += tree_cnt[id * 2 + 1][i];
  }
  return;
}

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie();
  cout.tie();
  int n, m;
  cin >> n >> m;
  for (int i = 1; i <= n; i++) {
    tree_cnt[i + base][0] = 1;
  }
  for (int i = base - 1; i > 0; i--) {
    tree_cnt[i][0] = tree_cnt[i * 2][0] + tree_cnt[i * 2 + 1][0];
  }
  for (int l, r, k, i = 0; i < m; i++) {
    cin >> l >> r >> k;
    collor_query(l, r + 1, k);
  }
  int res = 0;
  for (int i = 0; i < 8; i++) {
    res += ((tree_collor[1] | i) == green_mask ? tree_cnt[1][i] : 0);
  }
  cout << res;
  return 0;
}