#include <bits/stdc++.h>
using namespace std;
const int MAX_N = 1e5 + 1;
const int MOD = 1e9 + 7;
const int INF = 1e9;
const long long LINF = 1e18;
void solve() {
  int n;
  cin >> n;
  std::vector<pair<int, int>> v;
  int x, y;
  for (int i = 0; i < n; ++i) {
    cin >> x >> y;
    v.push_back(make_pair(x, y));
  }
  int j = 0;
  int ans;
  for (int i = 0; i < n; ++i) {
    if (v[i].second > j) {
      ans = max(j + 1, v[i].first);
      cout << ans << " ";
      j = ans;
    } else {
      cout << 0 << " ";
    }
  }
  cout << endl;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int tc;
  cin >> tc;
  for (int t = 1; t <= tc; t++) {
    solve();
  }
}
