#include <bits/stdc++.h>
const long long mod = 1000000007;
using namespace std;
template <typename T>
void printV(vector<T>& v) {
  for (int i = 0; i < (int)(v.size()); i++) cout << v[i] << " ";
  cout << endl;
}
template <typename T>
void printVs(vector<vector<T> >& v) {
  for (int i = 0; i < (int)(v.size()); i++) printV(v[i]);
}
const int N = 600000;
const char aa = 'a';
int main(int argc, const char* argv[]) {
  int n, a, d;
  cin >> n >> a >> d;
  vector<int> v(n), t(n);
  for (int i = 0; i < (int)(n); i++) cin >> t[i] >> v[i];
  vector<double> T(n);
  for (int i = 0; i < (int)(n); i++) {
    double tm = v[i] / (a + 0.0);
    if (tm * v[i] / 2 >= d)
      T[i] = sqrt(d * 2 / (a + 0.0));
    else
      T[i] = tm + (d - tm * v[i] / 2) / (v[i] + 0.0);
    T[i] += t[i];
    if (i) T[i] = max(T[i], T[i - 1]);
  }
  setprecision(10);
  for (int i = 0; i < (int)(n); i++) {
    cout << fixed;
    cout << T[i] << endl;
  }
}
