#include <bits/stdc++.h>
using namespace std;
int n;
double a, __d;
int main() {
  cin >> n >> a >> __d;
  double lastt = 0;
  while (n--) {
    double d = __d;
    double t, v;
    cin >> t >> v;
    double vget = v / a;
    double deltax = v * v / (2 * a);
    if (deltax >= d) {
      double addt = sqrt(2 * d / a);
      t += addt;
    } else {
      d -= deltax;
      t += vget;
      t += d / v;
    }
    t = max(t, lastt);
    cout << fixed << setprecision(10) << t << endl;
    lastt = t;
  }
  return 0;
}
