#include <bits/stdc++.h>
using namespace std;
struct truck {
  double t;
  double v;
  double f;
} T[100001];
int main() {
  int n;
  double a, d;
  cin >> n >> a >> d;
  double mb;
  for (int i = 0; i < n; i++) {
    cin >> T[i].t >> T[i].v;
    double t = T[i].v / a;
    double s = .5 * a * t * t;
    double total_time;
    if (s > d) {
      total_time = sqrt((d * 2) / a) + T[i].t;
    } else {
      double S = (d - s);
      total_time = (S / T[i].v) + t + T[i].t;
    }
    T[i].f = total_time;
    for (int j = i - 1; j >= 0; j--) {
      if (T[i].f - T[j].f <= 0.00000004) {
        T[i].f = T[j].f;
        break;
      } else
        break;
    }
    printf("%.5lf\n", T[i].f);
  }
  return 0;
}
