#include <bits/stdc++.h>
const int MAXINT = 2147483640;
const long long MAXLL = 9223372036854775800LL;
const long long MAXN = 1000000;
using namespace std;
int l[MAXN], r[MAXN];
int n;
int ans[MAXN];
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int T;
  cin >> T;
  while (T--) {
    cin >> n;
    for (int i = 1; i <= n; ++i) ans[i] = 0;
    for (int i = 1; i <= n; ++i) cin >> l[i] >> r[i];
    int t = l[1];
    ans[1] = t;
    for (int i = 2; i <= n; ++i) {
      if (r[i] <= t)
        ans[i] = 0;
      else {
        ans[i] = max(l[i], t + 1);
        t = ans[i];
      }
    }
    for (int i = 1; i <= n; ++i) cout << ans[i] << " ";
    cout << '\n';
  }
  return 0;
}
