#include <bits/stdc++.h>
using namespace std;
inline int cmp(double x, double y = 0, double tol = 1e-9) {
  return (x <= y + tol) ? (x + tol < y) ? -1 : 0 : 1;
}
int main() {
  int n;
  double a, d, t0, vm, t_vm, def, last = 0;
  scanf("%d %lf %lf", &n, &a, &d);
  def = sqrt(2 * d / a);
  for (int i = 0; i < n; ++i) {
    scanf("%lf %lf", &t0, &vm);
    t_vm = vm / a;
    if (t_vm < def)
      t_vm += (d - .5 * a * t_vm * t_vm) / vm;
    else
      t_vm = def;
    last = max(t_vm + t0, last);
    printf("%.10lf\n", last);
  }
  return 0;
}
