#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, a, d;
  cin >> n >> a >> d;
  double time;
  double lastTime = 0;
  int ti;
  int vm;
  for (int32_t i = (0); i < int32_t(n); ++i) {
    cin >> ti >> vm;
    int vi = 0;
    double time = vm * 1.0 / a;
    if (((0 + vm) * 1.0 / 2 * time) < d)
      time = time + (d - ((0 + vm) * 1.0 / 2 * time)) * 1.0 / vm;
    else
      time = sqrt(d * 2.0 / a);
    time += ti;
    if (time < lastTime) {
      time = lastTime;
    }
    printf("%.6f\n", time);
    lastTime = time;
  }
  return 0;
}
