#include <bits/stdc++.h>
using namespace std;
double caltime(int v, int a, int s) {
  double tt = v * 1.0 / a;
  double dd = a * tt * tt / 2.0;
  if (dd >= s * 1.0) return sqrt(2.0 * s / a);
  return tt + 1.0 * (s - dd) / v;
}
int main() {
  int n, a, d;
  double lst = -1.0;
  cin >> n >> a >> d;
  for (int i = 0; i < n; i++) {
    int ti, v;
    cin >> ti >> v;
    double tt = ti + caltime(v, a, d);
    lst = max(lst, tt);
    printf("%lf\n", lst);
  }
  return 0;
}
