#include <bits/stdc++.h>
using namespace std;
const int maxn = 2000000;
int xx[1111111], yy[1111111];
int pos[1111111], n, m, op[1111111], np[1111111], ff;
int owner[3333333], first[3333333];
int ans[1111111];
bool used[1111111];
void imp() {
  puts("-1");
  exit(0);
}
inline int sum(int x) {
  int r = 0;
  while (x >= 0) {
    r += first[x];
    x = (x & (x + 1)) - 1;
  }
  return r;
}
inline void add(int x, int d) {
  while (x <= maxn) {
    first[x] += d;
    x = (x | (x + 1));
  }
}
inline int getFirst(int x) {
  int l = -1, r = maxn;
  while (r - l > 1) {
    int mid = ((l + r) >> 1);
    if (sum(mid) >= x) {
      r = mid;
    } else {
      l = mid;
    }
  }
  return r;
}
int main() {
  scanf("%d%d", &n, &m);
  for (int i = 0; i < m; ++i) {
    scanf("%d%d", &xx[i], &yy[i]);
    --xx[i];
  }
  memset(owner, -1, sizeof(owner));
  memset(pos, -1, sizeof(pos));
  int ff = m;
  for (int i = 1; i <= n; ++i) {
    add(ff + i, 1);
  }
  for (int i = 0; i < m; ++i) {
    int &oldPlace = op[i];
    int &newPlace = np[i];
    int &x = xx[i];
    int &y = yy[i];
    oldPlace = getFirst(y);
    if ((pos[x] != -1 && oldPlace != pos[x]) ||
        (owner[oldPlace] != -1 && owner[oldPlace] != x)) {
      imp();
    }
    newPlace = ff--;
    owner[oldPlace] = -1;
    add(oldPlace, -1);
    add(newPlace, 1);
    pos[x] = newPlace;
    owner[newPlace] = x;
  }
  for (int i = m - 1; i >= 0; --i) {
    int &oldPlace = op[i];
    int &newPlace = np[i];
    int &x = xx[i];
    int &y = yy[i];
    pos[x] = oldPlace;
    owner[oldPlace] = x;
    add(oldPlace, 1);
    owner[newPlace] = -1;
    add(newPlace, -1);
  }
  memset(ans, -1, sizeof(ans));
  for (int i = 0; i < n; ++i)
    if (pos[i] != -1) {
      int p = sum(pos[i]);
      ans[p - 1] = i;
      used[i] = true;
    }
  int fx = 0;
  for (int i = 0; i < n; ++i)
    if (ans[i] == -1) {
      while (used[fx]) {
        ++fx;
      }
      ans[i] = fx;
      used[fx] = true;
    }
  for (int i = 0; i < n; ++i) {
    if (i > 0) {
      putchar(' ');
    }
    printf("%d", ans[i] + 1);
  }
  puts("");
  return 0;
}
