#include <bits/stdc++.h>
using namespace std;
const int N = 2e5;
int from[N], to[N];
int main() {
  cin.tie(NULL);
  ios_base::sync_with_stdio(0);
  int n, m;
  cin >> n >> m;
  vector<pair<int, int> > mst;
  set<pair<int, int> > freeEdges;
  for (int i = 0; i < (int)(m); ++i) {
    int w, isMST;
    cin >> w >> isMST;
    if (isMST) {
      mst.push_back(make_pair(w, i));
    } else {
      freeEdges.insert(make_pair(w, i));
    }
  }
  sort(mst.begin(), mst.end());
  for (int i = 0; i < (int)(n - 1); ++i) {
    int id = mst[i].second;
    from[id] = i;
    to[id] = i + 1;
  }
  int u = 0, v = 2;
  for (int i = 0; i < (int)(m - n + 1); ++i) {
    int cur = mst[v - 1].first;
    auto it = freeEdges.lower_bound(make_pair(cur, -1));
    if (freeEdges.empty() || it == freeEdges.end()) {
      cout << -1;
      return 0;
    }
    int id = it->second;
    from[id] = u;
    to[id] = v;
    --u;
    if (u == -1) {
      u = v - 1;
      ++v;
    }
    freeEdges.erase(it);
  }
  for (int i = 0; i < (int)(m); ++i) {
    cout << 1 + from[i] << ' ' << 1 + to[i] << endl;
  }
  return 0;
}
