#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, ind = 0;
  double a, d, t, v, prev = 0, res[100001];
  scanf("%d%lf%lf", &n, &a, &d);
  for (int i = 0; i < n; ++i) {
    scanf("%lf%lf", &t, &v);
    double T = v / a, x = 0.5 * a * T * T;
    if (x > d)
      t += sqrt((2 * d) / a);
    else
      t += (T + ((d - x) / v));
    if (t < prev) t = prev;
    prev = t, res[ind++] = t;
  }
  for (int i = 0; i < ind; ++i) printf("%.10lf\n", res[i]);
  return 0;
}
