#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  long double a, d, t = 0;
  cin >> n >> a >> d;
  long double dt = sqrt(2 * d / a);
  cout.precision(20);
  for (int i = 0; i < n; i++) {
    long double v, t0;
    cin >> t0 >> v;
    long double t1 = v / a;
    long double d1 = a * t1 * t1 / 2;
    if (d1 < d) {
      t1 += (d - d1) / v;
    } else {
      t1 = dt;
    }
    t1 += t0;
    if (t1 < t) t1 = t;
    t = t1;
    cout << t << endl;
  }
  return 0;
}
