#include <bits/stdc++.h>
using namespace std;
int pen[2000005];
void update(int ind, int add) {
  while (ind < 2000005) {
    pen[ind] += add;
    ind += ind & (-ind);
  }
}
int query(int ind) {
  int ret = 0;
  while (ind > 0) {
    ret = ret + pen[ind];
    ind = ind & (ind - 1);
  }
  return ret;
}
pair<int, int> r[2000005];
bool vis[2000005];
int getIndex(int y) {
  int sum = 0;
  int ind = 0;
  for (int i = 20; i >= 0; --i) {
    int nind = ind + (1 << i);
    if (nind < 2000005) {
      int nsum = sum + pen[nind];
      if (nsum < y) {
        sum = nsum;
        ind = nind;
      }
    }
  }
  return ind + 1;
}
int out[2000005];
int mapping[2000005];
void solve() {
  int n, m;
  scanf(" %d %d ", &n, &m);
  int pos = m + 1;
  for (int i = 1; i <= n; ++i) {
    r[pos + i] = {-1, i};
    update(pos + i, 1);
  }
  for (int i = 0; i < m; ++i) {
    int x, y;
    scanf("%d %d ", &x, &y);
    int ind = getIndex(y);
    if (vis[x]) {
      if (r[ind].first != x) {
        printf("-1\n");
        return;
      }
    } else {
      if (r[ind].first != -1) {
        printf("-1\n");
        return;
      }
    }
    update(ind, -1);
    update(pos, 1);
    r[pos] = r[ind];
    r[pos].first = x;
    vis[x] = true;
    --pos;
  }
  int p = 1;
  for (int i = 1; i <= n; ++i) {
    int ind = getIndex(i);
    if (r[ind].first == -1) {
      while (p <= n) {
        if (vis[p]) {
          ++p;
        } else {
          break;
        }
      }
      r[ind].first = p++;
    }
    out[r[ind].second] = r[ind].first;
  }
  for (int i = 1; i <= n; ++i) {
    printf("%d ", out[i]);
  }
}
int main() {
  solve();
  return 0;
}
