#include <bits/stdc++.h>
using namespace std;
int main() {
  double n, a, d;
  double ans, lastAns;
  scanf("%lf %lf %lf", &n, &a, &d);
  for (int i = 0; i < n; i++) {
    double t;
    double v;
    scanf("%lf %lf", &t, &v);
    double x = v / a;
    double dist = x * x * a / 2;
    if (dist < d) {
      double p = d - dist;
      ans = p / v + x;
    } else
      ans = sqrt(2 * d / a);
    ans += t;
    if (i > 0) ans = max(lastAns, ans);
    lastAns = ans;
    printf("%0.4lf \n", ans);
  }
  return 0;
}
