#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  double a, d;
  while (cin >> n >> a >> d) {
    double lastT = 0.0;
    for (int i = 0; i < n; i++) {
      double t, v;
      scanf("%lf %lf", &t, &v);
      double at = v / a;
      double ss = a * at * at / 2.0;
      double res = 0;
      if (ss >= d) {
        res += sqrt(2 * d / a);
      } else {
        res += at;
        double remaind = d - ss;
        res += remaind / v;
      }
      res += t;
      if (res < lastT) res = lastT;
      printf("%.9f\n", res);
      lastT = res;
    }
  }
  return 0;
}
