#include <bits/stdc++.h>
using namespace std;
int n;
double a, d, t, v, T;
double res[200005];
int main() {
  scanf("%d%lf%lf", &n, &a, &d);
  for (int i = 1; i <= n; ++i) {
    scanf("%lf%lf", &t, &v);
    T = v / a;
    if (0.5 * a * T * T + 1e-10 >= d) {
      res[i] = sqrt(2 * d / a) + t;
    } else {
      res[i] = t + T + (d - 0.5 * a * T * T) / v;
    }
    res[i] = max(res[i - 1], res[i]);
    printf("%.6lf\n", res[i]);
  }
  return 0;
}
