#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, a, d;
  scanf("%d %d %d", &n, &a, &d);
  double previous = 0;
  while (n--) {
    int t, v;
    scanf("%d %d", &t, &v);
    double next = 0;
    double ti = v * 1.0 / a;
    double di = a * ti * ti / 2.0;
    if (di - d > 1e-9) {
      double ll = 0, rr = ti;
      while (rr - ll > 1e-9) {
        double ti = (ll + rr) / 2.0;
        double di = a * ti * ti / 2.0;
        if (d - di > 1e-9)
          ll = ti;
        else
          rr = ti - 1e-9;
      }
      next = ll;
    } else
      next = ti + (d - di) / v;
    next += t;
    if (previous - next > 1e-9) next = previous;
    printf("%.12lf\n", next);
    previous = next;
  }
  return 0;
}
