#include <bits/stdc++.h>
using namespace std;
template <typename A, typename B>
string to_string(pair<A, B> p);
template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);
template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);
string to_string(const string& s) { return '"' + s + '"'; }
string to_string(const char* s) { return to_string((string)s); }
string to_string(bool b) { return (b ? "true" : "false"); }
string to_string(vector<bool> v) {
  bool first = true;
  string res = "{";
  for (int i = 0; i < static_cast<int>(v.size()); i++) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(v[i]);
  }
  res += "}";
  return res;
}
template <size_t N>
string to_string(bitset<N> v) {
  string res = "";
  for (size_t i = 0; i < N; i++) {
    res += static_cast<char>('0' + v[i]);
  }
  return res;
}
template <typename A>
string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto& x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}
template <typename A, typename B>
string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ")";
}
template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}
void debug_out() { cerr << endl; }
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}
const int maxn = 2e6 + 5;
const int maxm = 1e6 + 1;
int sum[maxn];
void add(int idx, int val) {
  while (idx < maxn) {
    sum[idx] += val;
    idx += idx & -idx;
  }
}
int query(int idx) {
  int res = 0;
  while (idx) {
    res += sum[idx];
    idx -= idx & -idx;
  }
  return res;
}
int val[maxn];
bool vis[maxn];
int ans[maxn];
int n, m;
int get_idx(int num) {
  int l = 1, r = maxn - 1;
  int ans = -1;
  while (l <= r) {
    int mid = l + r >> 1;
    if (query(mid) >= num) {
      ans = mid;
      r = mid - 1;
    } else {
      l = mid + 1;
    }
  }
  return ans;
}
int main() {
  scanf("%d %d", &n, &m);
  for (int i = 1; i <= n; i++) {
    add(i + maxm, 1);
  }
  int x, y;
  int now = maxm;
  while (m--) {
    scanf("%d %d", &x, &y);
    int idx = get_idx(y);
    if (idx <= maxm) {
      if (val[idx] != x) {
        puts("-1");
        return 0;
      }
    } else {
      if (vis[x]) {
        puts("-1");
        return 0;
      } else {
        ans[idx - maxm] = x;
        vis[x] = 1;
      }
    }
    val[now] = x;
    add(idx, -1);
    add(now, 1);
    now--;
  }
  int j = 1;
  for (int i = 1; i <= n; i++) {
    if (!ans[i]) {
      while (vis[j]) j++;
      ans[i] = j;
      vis[j] = 1;
    }
    printf("%d ", ans[i]);
  }
  puts("");
  return 0;
}
