#include <bits/stdc++.h>
using namespace std;
struct train {
  double t = 0, v = 0, time = 0;
};
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  double ta, s, n, a, d, mx = -1;
  cin >> n >> a >> d;
  vector<train> trn(n);
  for (int i = 0; i < n; i++) {
    cin >> trn[i].t >> trn[i].v;
    ta = trn[i].v / a;
    s = (trn[i].v) * (trn[i].v) / (2 * a);
    if (s > d)
      trn[i].time = sqrt(2 * d / a) + trn[i].t;
    else
      trn[i].time = ta + (d - s) / trn[i].v + trn[i].t;
    trn[i].time = max(mx, trn[i].time);
    mx = trn[i].time;
    cout << setprecision(12) << trn[i].time << "\n";
  }
}
