/**
* author: Haunted_Cpp
**/
#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("Ofast")
#pragma GCC target("fma,sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
#pragma GCC optimize("unroll-loops")
template<typename T> ostream &operator << (ostream &os, const vector<T> &v) { os << '{'; string sep; for (const auto &x : v) os << sep << x, sep = ", "; return os << '}'; }
template<typename T, size_t size> ostream &operator << (ostream &os, const array<T, size> &arr) { os << '{'; string sep; for (const auto &x : arr) os << sep << x, sep = ", "; return os << '}'; }
template<typename A, typename B> ostream &operator << (ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ", " << p.second << ')'; }
void debug_out() { cerr << endl; }
template<typename Head, typename... Tail> void debug_out(Head H, Tail... T) { cerr << ' ' << H; debug_out(T...); }
#ifdef LOCAL
#define debug(...) cerr << "(" << #__VA_ARGS__ << "):", debug_out(__VA_ARGS__)
#else
#define debug(...) 47
#endif
class SegmentTree {
private:
struct Node {
int mn, lazy;
Node() {
mn = 1e9;
lazy = -1;
}
};
const int LO, HI;
vector<Node> seg;
void push(int l, int r, int node) {
if (seg[node].lazy == -1) return;
seg[node].mn = seg[node].lazy;
if (l != r) {
seg[2 * node + 1].lazy = seg[node].lazy;
seg[2 * node + 2].lazy = seg[node].lazy;
}
seg[node].lazy = -1;
}
void range_set(int ql, int qr, int delta, int l, int r, int node) {
push(l, r, node);
if (l > qr || r < ql) return;
if (l >= ql && r <= qr) {
seg[node].lazy = delta;
push(l, r, node);
return;
}
const int mid = l + (r - l) / 2;
range_set(ql, qr, delta, l, mid, 2 * node + 1);
range_set(ql, qr, delta, mid + 1, r, 2 * node + 2);
seg[node].mn = min(seg[2 * node + 1].mn, seg[2 * node + 2].mn);
}
int range_query(int ql, int qr, int l, int r, int node) {
push(l, r, node);
if (l > qr || r < ql) return 1e9;
if (l >= ql && r <= qr) return seg[node].mn;
const int mid = l + (r - l) / 2;
return min(range_query(ql, qr, l, mid, 2 * node + 1), range_query(ql, qr, mid + 1, r, 2 * node + 2));
}
void solve(int l, int r, int node) {
push(l, r, node);
if (l == r) {
if (seg[node].mn > 1e7) cout << 0 << '\n';
else cout << seg[node].mn << ' ';
return;
}
const int mid = l + (r - l) / 2;
solve(l, mid, 2 * node + 1);
solve(mid + 1, r, 2 * node + 2);
}
public:
SegmentTree(int n) : LO(0), HI(n - 1) {
seg.clear();
seg.resize(4 * n);
}
void range_set(int ql, int qr, int delta) {
range_set(ql, qr, delta, LO, HI, 0);
}
int rmq(int ql, int qr) {
return range_query(ql, qr, LO, HI, 0);
}
void solve() {
solve(LO, HI, 0);
}
};
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
int n, m;
cin >> n >> m;
vector<tuple<int, int, int>> arr(m);
for (int i = 0; i < m; i++) {
int st, et, w;
cin >> st >> et >> w;
arr[i] = {st, et, w};
}
if (n <= 10) {
vector<int> ans(n);
iota(ans.begin(), ans.end(), 0);
do {
for (int i = 0; i < m; i++) {
const int st = get<0>(arr[i]);
const int et = get<1>(arr[i]);
const int mn = get<2>(arr[i]);
const int is = *min_element(ans.begin() + st, ans.begin() + et + 1);
if (is != mn) {
goto fim;
break;
}
}
for (auto to : ans) cout << to << ' ';
return 0;
fim:;
} while(next_permutation(ans.begin(), ans.end()));
for (int i = 0; i < n; i++) {
cout << -1 << ' ';
}
return 0;
} else {
sort(arr.begin(), arr.end(), [&](auto x, auto y) {
return get<2>(x) < get<2>(y);
});
SegmentTree seg(n);
for (int i = 0; i < m; i++) {
const int st = get<0>(arr[i]);
const int et = get<1>(arr[i]);
const int mn = get<2>(arr[i]);
seg.range_set(st, et, mn);
}
for (int i = 0; i < m; i++) {
const int st = get<0>(arr[i]);
const int et = get<1>(arr[i]);
const int mn = get<2>(arr[i]);
const int is = seg.rmq(st, et);
if (is != mn) {
for (int j = 0; j < n; j++) {
cout << -1 << ' ';
}
cout << '\n';
return 0;
}
}
seg.solve();
cout << '\n';
}
return 0;
}
