#include <bits/stdc++.h>
using namespace std;
int main(int argc, char const *argv[]) {
  int n, a, d;
  vector<long double> so;
  cin >> n >> a >> d;
  for (int i = 0; i < n; i++) {
    int t, v;
    cin >> t >> v;
    if ((long double)v * v < (long double)2 * a * d)
      so.push_back((long double)t + (long double)v / 2 / a +
                   (long double)d / v);
    else
      so.push_back((long double)t + sqrt(2 * (long double)d / a));
  }
  if (so.size() >= 1) cout << fixed << setprecision(14) << so[0] << endl;
  for (int i = 1; i < so.size(); i++) {
    if (so[i] < so[i - 1]) so[i] = so[i - 1];
    cout << so[i] << endl;
  }
  return 0;
}
