#include <bits/stdc++.h>
using namespace std;
const double eps = 1e-10;
int n, a, d;
int dt, dv;
double getTime(double maxv) {
  double t = maxv / a;
  double s = a * t * t / 2;
  if (s > d + eps) {
    return sqrt(d * 2.0 / a);
  } else {
    return t + (d - s) / maxv;
  }
}
int main() {
  double pt = -0.0, t;
  scanf("%d %d %d", &n, &a, &d);
  for (int i = 0; i < n; ++i) {
    scanf("%d %d", &dt, &dv);
    t = dt + getTime(dv);
    if (t > pt + eps) {
      printf("%lf\n", t);
      pt = t;
    } else
      printf("%lf\n", pt);
  }
  return 0;
}
