#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  double a, d;
  cin >> n >> a >> d;
  double res = 0;
  while (n--) {
    double t, v;
    cin >> t >> v;
    double tt = v / a;
    double xx = d - a * tt * tt / 2.0;
    if (xx < 0)
      tt = sqrt(2 * d / a);
    else
      tt += xx / v;
    res = max(res, tt + t);
    printf("%.10f\n", res);
  }
  return 0;
}
