#include<bits/stdc++.h>
using namespace std;
#define file "a"
// #define int long long
#define ll long long
#define pii pair<int, int>
#define pli pair<ll, int>
#define fi first
#define se second
#define sz(a) (int)a.size()
#define pb push_back
#define mask(i) (1 << i)
const int N = 1e6, inf = 1e9;
mt19937_64 rd(chrono::steady_clock::now().time_since_epoch().count());
int rad(int l, int r) { return l + rd() % (r - l + 1); }
void MAX(int &a, int b) { a = max(a, b); }
void MIN(int &a, int b) { a = min(a, b); }
struct stt
{
int l, r, id;
bool operator < (const stt &o) const
{
return id > o.id;
}
};
int n, q;
int kq[N + 2];
bool vis[N + 2];
stt a[N + 2];
int x[15], mn[15][15];
bool kt[15], ok, run;
vector<pii> g[15];
void track(int i)
{
if (ok) return;
if (i == n)
{
ok = 1;
for (int j = 0; j < n; j++) cout << x[j] << " ";
return;
}
for (int j = 0; j < n; j++)
if (!kt[j])
{
kt[j] = 1;
x[i] = j;
mn[i][i] = j;
for (int p = i - 1; p >= 0; p--)
mn[p][i] = min(mn[p][i - 1], j);
run = 1;
for (pii x : g[i])
{
int l = x.fi, val = x.se;
if (mn[l][i] != val) { run = 0; break; }
}
if (run) track(i + 1);
kt[j] = 0;
}
}
void Sub1()
{
for (int i = 1; i <= q; i++) g[a[i].r].pb({a[i].l, a[i].id});
track(0);
if (!ok) cout << -1;
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
// if (fopen(file".inp", "r"))
// {
// freopen(file".inp", "r", stdin);
// freopen(file".out", "w", stdout);
// }
cin >> n >> q;
for (int i = 1; i <= q; i++) cin >> a[i].l >> a[i].r >> a[i].id;
sort(a + 1, a + q + 1);
if (max(n, q) <= 10) return Sub1(), 0;
}
