#include <bits/stdc++.h>
using namespace std;
int main() {
  cin.tie(0);
  cin.sync_with_stdio(0);
  int n;
  double a, d;
  cin >> n >> a >> d;
  int ti, si;
  double last = 0;
  cout << fixed << setprecision(8);
  for (int i = 0; i < n; i++) {
    cin >> ti >> si;
    double dd = (long long)si * (long long)si / (2 * a);
    double time_taken;
    if (d > dd)
      time_taken = si / a + (d - dd) / (double)si;
    else
      time_taken = sqrt(2 * d / a);
    if (time_taken + ti > last) {
      cout << time_taken + ti << "\n";
      last = time_taken + ti;
    } else
      cout << last << "\n";
  }
}
