#include <bits/stdc++.h>
using namespace std;
int main() {
  int i;
  double n, a, d, t, v;
  double bf, bb;
  while (cin >> n >> a >> d) {
    cin >> t >> v;
    if (((v / a) * (v / 2)) < d) {
      bf = d / v + (0.5 * v) / a + t;
    } else
      bf = t + sqrt((2 * d) / a);
    cout << setiosflags(ios::fixed) << setprecision(10) << bf << endl;
    for (i = 1; i < n; i++) {
      cin >> t >> v;
      if (((v / a) * v) < d * 2)
        bb = d / v + (0.5 * v) / a + t;
      else
        bb = t + sqrt((2 * d) / a);
      if (bb > bf) bf = bb;
      cout << setiosflags(ios::fixed) << setprecision(10) << bf << endl;
    }
  }
  return 0;
}
