#include <bits/stdc++.h>
using namespace std;

struct node {
	int y, value, cnt;

	node *l, *r;

	node(int value): value(value), l(nullptr), r(nullptr), y(rand() * rand()), cnt(1)
	{}

	~node() {
		if(l) delete(l);
		if(r) delete(r);
	}
};

int cnt(node* t) {
	return t? t->cnt : 0;
}

void upd_cnt(node*& t) {
	if(!t) return;
	t->cnt = cnt(t->l) + cnt(t->r) + 1;
}

pair<node*, node*> split(node*& t, int x) {
	if(!t) return {nullptr, nullptr};
	int cur_key = cnt(t->l) + 1;
	if(cur_key < x) {
		auto res = split(t->r, x - cur_key);
		t->r = res.first;
		upd_cnt(t); upd_cnt(res.second);
		return {t, res.second};
	} else {
		auto res = split(t->l, x);
		t->l = res.second;
		upd_cnt(t); upd_cnt(res.second);
		return {res.first, t};
	}
}

node* merge(node* l, node* r) {
	if(!l || !r) return l? l : r;

	if(l->y > r->y) {
		l->r = merge(l->r, r);
		upd_cnt(l);
		return l;
	} else {
		r->l = merge(l, r->l);
		upd_cnt(r);
		return r;
	}
}

int exist(node* t, int x, int add = 0) {
	if(!t) return false;
	int cur_x = add + cnt(t->l);
	if(cur_x == x) return t->value;

	if(cur_x < x) return exist(t->r, x, add + cnt(t->l) + 1);
	else return exist(t->l, x, add);
}

void insert(node*& t, node*& n, int idx) {
	auto res = split(t, idx);
	t = merge(merge(res.first, n), res.second);
	upd_cnt(t);
}

void erase(node*&t, int idx, int add = 0) {
	if(!t) return;
	int cur_key = add + cnt(t->l);
	if(cur_key == idx) {
		t = merge(t->l, t->r);
		upd_cnt(t);
		return;
	}

	if(cur_key < idx) erase(t->r, idx, add + cnt(t->l) + 1);
	else erase(t->l, idx, add);
	upd_cnt(t);
}

struct query {
	int val, idx;

};

int to_start = 0;
int used[1000001];
int ans[1000001];
query q[1000001];

int main() {
	srand(time(0));
	ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	node* root = nullptr;
	int N, m;
	cin >> N >> m;
	for(int i = 0; i < m; i++) {
		cin >> q[i].val >> q[i].idx;
		q[i].idx--;
	}

	for(int i = 0; i < N; i++) {
		node* n = new node(0);
		insert(root, n, 1);
	}

	for(int i = 0; i < m; i++) {
		int current = exist(root, q[i].idx);
		if(current && current != q[i].val) {
			cout << -1;
			return 0;
		}

		erase(root, q[i].idx);
		node* n = new node(q[i].val);
		insert(root, n, 1);
	}


	for(int i = m-1; i >= 0; i--) {
		node* n = new node(exist(root, 0));
		erase(root, 0);
		insert(root, n, q[i].idx + 1);
	}

	for(int i = 0; i < N; i++) {
		int j = exist(root, i);
		if(used[j] == true) {
			cout << -1;
			return 0;
		}
		if(j) used[j] = true;
	}
	int pos = 1;
	for(int i = 0; i < N; i++) {
		int cur = exist(root, i);
		if(!cur) {
			while(used[pos]) pos++;
			cur = pos++;
		}

		ans[i] = cur;
	}

	for(int i = 0; i < N; i++) cout << ans[i] << " ";

}