#include <bits/stdc++.h>
using namespace std;
const double inv = 1.0e8;
int n;
double a, d;
double p;
double v, t;
int main() {
  scanf("%d", &n);
  int ia, id;
  scanf("%d", &ia);
  scanf("%d", &id);
  a = (double(ia));
  d = (double(id));
  p = 0.0;
  for (int i = 0; i < n; ++i) {
    int iv, it;
    scanf("%d", &it);
    scanf("%d", &iv);
    v = (double(iv));
    t = (double(it));
    double t0 = v / a;
    double tr;
    if (t0 * t0 * a / 2.0 > d) {
      tr = sqrt(2.0 * d / a);
    } else {
      tr = t0 + ((d - (a * t0 * t0 / 2.0)) / v);
    }
    p = max(t + tr, p);
    printf("%.12f\n", p);
  }
  return 0;
}
