#include <bits/stdc++.h>   using namespace std;   void init_code() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);   }   int main() {     init_code();     int t;     cin >> t;     while (t--) {       int n;       cin >> n;       vector<pair<int, int>> v;       vector<pair<int, int>> v1;       for (int i = 0; i < n; i++) {         int x, y;         cin >> x >> y;         v1.push_back({x, y});         v.push_back({x, y});       }       sort(v.begin(), v.end());       int st = v[0].first;       int ed = v[0].second;       int cnt = 1;       unordered_map<int, int> mp;       mp[st] = 1;       for (int i = 1; i < n; i++) {         if (v[i].first <= ed) {           mp[v[i].first] = cnt;           ed = max(ed, v[i].second);         } else {           st = v[i].first;           ed = v[i].second;           if (cnt == 1) {             cnt++;           }           mp[v[i].first] = cnt;         }       }       if (cnt < 2) {         cout <<  -1  << endl;       } else {         for (int i = 0; i < v1.size(); i++) {           cout << mp[v1[i].first] <<    ;         }         cout << endl;       }     }     return 0;   }   