#include <bits/stdc++.h>
using namespace std;
double a, d;
double pre(double v) {
  if (d >= (v * v) / (2.0 * a)) {
    double x = v / a;
    double y = d - ((v * v) / (2.0 * a));
    double out = x + (y / (v));
    return out;
  } else {
    double out = sqrt((2.0 * d) / a);
    return out;
  }
}
int main() {
  int n;
  cin >> n >> a >> d;
  double arr[n][2];
  double time[n];
  for (int i = 0; i < n; i++) {
    scanf("%lf%lf", &arr[i][0], &arr[i][1]);
    double x = pre(arr[i][1]);
    time[i] = x + arr[i][0];
    if (i != 0 && time[i] < time[i - 1]) {
      time[i] = time[i - 1];
    }
    printf("%.6f\n", time[i]);
  }
  return 0;
}
