#include <bits/stdc++.h>
using namespace std;
int main() {
  int i, n;
  double a, d, prev, t, s, fin, x, vi, ti;
  cin >> n >> a >> d;
  prev = 0.;
  for (i = 0; i < n; i++) {
    cin >> ti >> vi;
    t = vi / a;
    s = (vi * vi) / (2. * a);
    if (s <= d) {
      x = d - s;
      fin = ti + t + x / vi;
    } else {
      fin = ti + sqrt((2. * d) / a);
    }
    if (prev < fin) prev = fin;
    printf("%.8lf\n", prev);
  }
  return 0;
}
