#include <bits/stdc++.h>
using namespace std;
int main() {
  double n, a, d;
  cin >> n >> a >> d;
  vector<int> t;
  vector<int> v;
  double prev = 0;
  int bit = 1;
  for (int i = 0; i < n; i++) {
    double t1, v1;
    cin >> t1 >> v1;
    double t2 = 0, t3 = 0, tot = 0;
    double dis = 0;
    t2 = (double)(v1) / double(a);
    dis = a * (t2) * (t2);
    dis = (float)dis / (float)2;
    if (dis >= d) {
      double velo = 2 * a * d;
      velo = sqrt(velo);
      t2 = velo / a;
      tot = t2 + (double)t1;
    } else {
      dis = d - dis;
      t3 = (double)dis / (double)v1;
      tot = (double)t2 + t3 + (double)t1;
    }
    if (tot > prev || bit == 1) {
      cout << setprecision(12) << tot << endl;
      prev = tot;
      bit = 0;
    } else {
      cout << setprecision(12) << prev << endl;
      bit = 0;
    }
  }
}
