#include <bits/stdc++.h>
using namespace std;
int n;
double a, d;
int main() {
  double ans, s = 0, t, v, tt;
  scanf("%d%lf%lf", &n, &a, &d);
  for (int i = 0; i < n; i++) {
    scanf("%lf%lf", &t, &v);
    tt = v / a;
    if (sqrt(2 * d / a) <= tt)
      ans = t + sqrt(2 * d / a);
    else
      ans = t + tt + (d - 0.5 * a * tt * tt) / v;
    printf("%.10lf\n", max(ans, s));
    s = max(ans, s);
  }
  return 0;
}
