#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  double a, d, t, v, t1, t2, prev = -1, curr, ans, area;
  scanf("%d %lf %lf", &n, &a, &d);
  for (int i = 0; i < n; ++i) {
    scanf("%lf %lf", &t, &v);
    t1 = v / a;
    area = t1 * v * .5;
    if (area > d) {
      curr = t + sqrt(2. * d / a);
    } else {
      t2 = (d - area) / v;
      curr = t + t1 + t2;
    }
    if (curr > prev) {
      ans = curr;
      prev = curr;
    } else {
      ans = prev;
    }
    printf("%.10f\n", ans);
  }
}
