#include <bits/stdc++.h>
using namespace std;
long long n;
double a, d;
double calcT(double st, double sp) {
  double spup = min(sp / a, sqrt(2 * d / a));
  double offset = spup / 2 * spup * a;
  double unif = (d - offset) / sp;
  return st + unif + spup;
}
int main() {
  std::ios_base::sync_with_stdio(false);
  cin >> n >> a >> d;
  cout << fixed << setprecision(6);
  double prev = 0;
  for (int i = 0; i < int(n); ++i) {
    double v, t;
    cin >> t >> v;
    double cur = calcT(t, v);
    cout << max(cur, prev) << "\n";
    prev = max(cur, prev);
  }
  return 0;
}
