#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, a, d;
  cin >> n >> a >> d;
  double pre = 0.0;
  for (int i = 0; i < (n); ++i) {
    int start, speed;
    cin >> start >> speed;
    int v = speed;
    double next = 1.0 * speed / a;
    double dis = 0.5 * speed * speed / a;
    if (dis > d) {
      next = sqrt(2.0 * d / a);
    } else {
      next += (d - dis) / v;
    }
    next += start;
    next = max(next, pre);
    printf("%.5lf\n", next);
    pre = next;
  }
  return 0;
}
