#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m;
  scanf("%d %d", &n, &m);
  vector<int> vec(n + 1, 0);
  vector<pair<int, pair<int, int>>> arr;
  for (int i = 0; i < m; i++) {
    int si, di, ci;
    scanf("%d %d %d", &si, &di, &ci);
    arr.push_back(make_pair(di, make_pair(si, ci)));
  }
  bool is_possible = true;
  for (int i = 1; i <= n; i++) {
    bool exam_time = false;
    for (int j = 0; j < m; j++) {
      if (arr[j].first == i) {
        exam_time = true;
        if (arr[j].second.second != 0) {
          is_possible = false;
        } else {
          vec[i] = m + 1;
        }
        break;
      }
    }
    if (exam_time) continue;
    int best = -1, mini = (int)1e9;
    for (int j = 0; j < m; j++) {
      if (arr[j].first > i && arr[j].second.first <= i &&
          arr[j].second.second != 0) {
        if (arr[j].first < mini) {
          mini = arr[j].first;
          best = j;
        }
      }
    }
    if (best != -1) {
      vec[i] = best + 1;
      arr[best].second.second--;
    }
  }
  if (is_possible) {
    for (int i = 1; i <= n; i++) {
      printf("%d ", vec[i]);
    }
  } else {
    printf("-1\n");
  }
  return 0;
}
