#include <bits/stdc++.h>
using namespace std;
double a, d;
int n;
double tCome(double start, double v) {
  double tAcc = v / a;
  if (((tAcc) * (tAcc)) * a / 2 > d) {
    return sqrt(2 * d / a) + start;
  } else {
    double ans = ((d - ((tAcc) * (tAcc)) * a / 2) / v) + tAcc;
    return ans + start;
  }
}
int main() {
  cin.sync_with_stdio(false);
  cout.sync_with_stdio(false);
  cin >> n >> a >> d;
  double tMax = 0, l, r;
  for (int i = 0; i < n; i++) {
    cin >> l >> r;
    tMax = max(tMax, tCome(l, r));
    printf("%.4f\n", tMax);
  }
  return 0;
}
