#include <bits/stdc++.h>
using namespace std;
template <typename TF>
void write_debug_output(ostream &out, TF const &f) {
  out << f << std::endl;
}
template <typename TF, typename... TR>
void write_debug_output(ostream &out, TF const &f, TR const &...rest) {
  out << f << " ";
  write_debug_output(out, rest...);
}
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pdd = pair<double, double>;
using vi = vector<int>;
using vii = vector<pii>;
using vll = vector<ll>;
using vs = vector<string>;
const int DR[] = {-1, 0, 1, 0, -1, 1, 1, -1};
const int DC[] = {0, -1, 0, 1, -1, -1, 1, 1};
const double PI = acos(-1.0);
const double EPS = 1e-9;
const int MOD = 1e9 + 7;
const int INF = 1073741823;
const ll INFLL = 4e18;
const int MAX = 100;
int N, M, ed[MAX + 5], cost[MAX + 5];
vi st[MAX + 5], ans;
set<int> dl;
void read() {
  cin >> N >> M;
  for (int i = (int)1; i <= (int)M; i++) {
    int s, d, c;
    cin >> s >> d >> c;
    st[s].push_back(d);
    ed[d] = i;
    cost[i] = c;
  }
}
void solve() {
  for (int day = (int)1; day <= (int)N; day++) {
    for (int d : st[day]) dl.insert(d);
    if (ed[day] != 0) {
      if (cost[ed[day]] > 0) {
        cout << "-1\n";
        return;
      } else
        ans.push_back(M + 1);
    } else {
      if (!dl.empty()) {
        int ex = ed[*dl.begin()];
        cost[ex]--;
        if (cost[ex] == 0) dl.erase(dl.begin());
        ans.push_back(ex);
      } else
        ans.push_back(0);
    }
  }
  for (int x : ans) cout << x << " ";
  cout << "\n";
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int TC = 1;
  for (int tc = (int)1; tc <= (int)TC; tc++) {
    read();
    solve();
  }
}
