#include <bits/stdc++.h>
const int MAXN = 2e7 + 7;
using namespace std;
long long int power(long long int x, long long int y) {
  long long int res = 1;
  while (y > 0) {
    if (y & 1) {
      res = (res * x) % 1000000007;
    }
    x = (x * x) % 1000000007;
    y = y >> 1;
  }
  return res;
}
std::vector<int> divi[100004];
void divisor(int n) {
  for (int i = 1; i <= n; i++) {
    for (int j = i; j <= n; j += i) {
      divi[j].push_back(i);
    }
  }
}
int L[2003][2003][2][2], R[2003][2003][2][2];
int a[2100];
int solve(int l, int r, int x, int y) {
  if (l > r) return 0;
  if (x > y) return 0;
  if (l == r) {
    if (a[l] >= x && a[l] <= y) return 1;
    return 0;
  }
  if (L[l][r][x][y] != -1) return L[l][r][x][y];
  int ans = max(solve(l + 1, r, x, y), solve(l, r - 1, x, y));
  if (a[l] >= x && a[l] <= y) ans = max(ans, 1 + solve(l + 1, r, a[l], y));
  if (a[r] <= y && a[r] >= x) {
    ans = max(ans, 1 + solve(l, r - 1, x, a[r]));
  }
  return L[l][r][x][y] = ans;
}
int solve2(int l, int r, int x, int y) {
  if (l > r) return 0;
  if (x < y) return 0;
  if (l == r) {
    if (a[l] <= x && a[l] >= y) return 1;
    return 0;
  }
  if (R[l][r][x][y] != -1) return R[l][r][x][y];
  int ans = max(solve2(l + 1, r, x, y), solve2(l, r - 1, x, y));
  if (a[l] <= x && a[l] >= y) ans = max(ans, 1 + solve2(l + 1, r, a[l], y));
  if (a[r] >= y && a[l] <= x) {
    ans = max(ans, 1 + solve2(l, r - 1, x, a[r]));
  }
  return R[l][r][x][y] = ans;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int n, m;
  cin >> n >> m;
  vector<vector<int>> v;
  for (int i = 0; i < m; i++) {
    int x, b;
    cin >> x >> b;
    v.push_back({x, 1 - b, i});
  }
  sort(v.begin(), v.end());
  vector<pair<int, int>> edges(m);
  long long int nodes = 1;
  int cycle_node = 3;
  int p = 2;
  for (int i = 0; i < m; i++) {
    int e = v[i][2];
    int w = v[i][0];
    if (v[i][1] == 0) {
      edges[e] = {1, nodes + 1};
      nodes++;
    } else {
      long long int val = nodes * (nodes - 1);
      val = val / 2;
      if (val <= i) {
        cout << -1 << endl;
        return 0;
      } else {
        edges[e] = {p, cycle_node};
        p++;
        if (p == cycle_node) {
          p = 2;
          cycle_node++;
        }
      }
    }
  }
  for (int i = 0; i < m; i++) {
    cout << edges[i].first << " " << edges[i].second << endl;
  }
  return 0;
}
