#include <bits/stdc++.h>
using namespace std;
int main(int argc, char *argv[]) {
  cout.precision(16);
  double prev = 0;
  double n, a, d;
  cin >> n >> a >> d;
  int i;
  for (i = 0; i < n; ++i) {
    double t, v;
    cin >> t >> v;
    double p = v / a;
    double q = 0.5 * a * p * p;
    double r = d - q;
    double s = 0;
    if (r >= 0) {
      s = (d - q) / v;
    } else {
      p = sqrt((2.0 * d) / a);
    }
    t += p;
    t += s;
    if (prev > t) {
      t = prev;
    }
    cout << t << endl;
    prev = t;
  }
  return 0;
}
