#include <bits/stdc++.h>
using namespace std;
void solve() {
  long long n, a, d, t, v;
  double ans;
  cin >> n >> a >> d;
  double t2 = (2.0000000 * d) / (double)a;
  t2 = sqrt(t2);
  double prev = -1.0000000;
  for (long long i = 0; i < n; i++) {
    cin >> t >> v;
    double t1 = ((double)v / a);
    if (t2 > t1) {
      double disc = (0.5000000 * a * t1 * t1);
      double rem = d - disc;
      ans = t1 + (rem / v);
    } else
      ans = t2;
    ans += t;
    if (ans < prev) ans = prev;
    cout << fixed << setprecision(10) << ans << "\n";
    prev = ans;
  }
}
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long t = 1;
  while (t--) solve();
}
