#include <bits/stdc++.h>
using namespace std;
int main() {
  int i, j, k;
  int n;
  double a, d;
  cin >> n;
  cin >> a >> d;
  double last = 0.;
  for (int h = 0; h < n; ++h) {
    double t, v;
    cin >> t >> v;
    double time = (v / (double)a);
    double dist = (time * time * (double)a) / 2.;
    if (dist > (double)d) {
      time = sqrt((((double)d) * 2.) / (double)a);
      time += t;
      last = max(last, time);
      printf("%.10lf\n", last);
    } else {
      double rest = (double)d - dist;
      time += rest / v;
      time += t;
      last = max(last, time);
      printf("%.10lf\n", last);
    }
  }
  return 0;
}
