#include <bits/stdc++.h>
using namespace std;
#define all(x) x.begin(), x.end()
#define mod 1000000007
#define sp << " " <<
#define endl << '\n'
int N, Q;
class Tree{
public:
vector<int> commoncontainer;
struct dat{
int say0 = 1;
int l;
int r;
dat* lft;
dat* rgt;
};
void copy(dat* root1, dat* root2){ // root2 = root1
root2->l = root1->l;
root2->r = root1->r;
root2->lft = root1->lft;
root2->rgt = root1->rgt;
root2->say0 = root1->say0;
}
private:
void _init(dat* root, int l, int r){
root->l = l;
root->r = r;
if (l == r)
return;
root->rgt = new dat;
root->lft = new dat;
int m = (l + r) >> 1;
_init(root->lft, l, m);
_init(root->rgt, m + 1, r);
root->say0 = root->lft->say0 + root->rgt->say0;
}
void _update(int l, int r, dat* root){
if (l <= root->l && root->r <= r){
root->say0 = 0;
return;
}
if (root->say0 == 0)
return;
if (root->lft->r >= l){
dat* eski = root->lft;
root->lft = new dat;
copy(eski, root->lft);
_update(l, r, root->lft);
}
if (root->rgt->l <= r){
dat* eski = root->rgt;
root->rgt = new dat;
copy(eski, root->rgt);
_update(l, r, root->rgt);
}
root->say0 = root->lft->say0 + root->rgt->say0;
}
int _first0(int l, int r, dat* root, int s){
if (commoncontainer[s] >= root->say0)
return -1;
if (root->l == root->r){
commoncontainer[s]++;
return root->l;
}
if (root->lft->r >= l && root->lft->say0 - commoncontainer[(s << 1)]){
int k = _first0(l, r, root->lft, s << 1);
if (k != -1){
commoncontainer[s]++;
return k;
}
}
if (root->rgt->l <= r && root->rgt->say0 - commoncontainer[(s << 1) | 1]){
int k = _first0(l, r, root->rgt, (s << 1) | 1);
if (k != -1){
commoncontainer[s]++;
return k;
}
}
return -1;
}
public:
void init(int size, dat* root){
commoncontainer.resize(size * 4);
_init(root, 0, size);
}
void update(int l, int r, dat* root){
_update(l, r, root);
}
int findleft0(dat* root, int l, int r){
return _first0(l, r, root, 1);
}
};
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
cin >> N >> Q;
Tree tre;
vector<vector<array<int, 2>>> querys(N);
vector<Tree::dat*> roots(N);
for (int i = 0; i < Q; i++){
int a, b, c;
cin >> a >> b >> c;
querys[c].push_back({ a, b });
}
roots[N - 1] = new Tree::dat;
tre.init(N, roots[N - 1]);
for (int i = N - 2; i >= 0; i--){
roots[i] = new Tree::dat;
tre.copy(roots[i + 1], roots[i]);
for (auto j : querys[i + 1]){
tre.update(j[0], j[1], roots[i]);
}
}
vector<int> ret(N);
for (int i = 0; i < N; i++){
int l = 0, r = N - 1;
for (auto o : querys[i]){
l = max(l, o[0]);
r = min(r, o[1]);
}
int k = tre.findleft0(roots[i], l, r);
if (r < l || k == -1){
for (int j = 0; j < N; j++){
cout << -1 sp "";
}
return 0;
}
ret[k] = i;
}
for (auto u : ret){
cout << u sp "";
}
return 0;
}
