#include <bits/stdc++.h>
using namespace std;
double n, d, a, v, k, ma;
int main() {
  cin >> n >> a >> d;
  for (int i = 0; i < n; i++) {
    cin >> k >> v;
    if ((v / a) * (v / a) / 2.0 * a >= d) {
      ma = max(sqrt(d / a * 2.0) + k, ma);
      cout << fixed << setprecision((10)) << ma << endl;
    } else {
      ma = max((d + a * (v / a) * (v / a) / 2) / v + k, ma);
      cout << fixed << setprecision((10)) << ma << endl;
    }
  }
  return 0;
}
