#include <bits/stdc++.h>
using namespace std;
int main() {
  double a, d, t, v, pre = -1, cc, res;
  int n;
  scanf("%d%lf%lf", &n, &a, &d);
  while (n--) {
    scanf("%lf%lf", &t, &v);
    cc = v * v / (2 * a);
    if (cc >= d)
      res = t + sqrt(2 * d / a);
    else
      res = (d - cc) / v + v / a + t;
    if (res < pre) res = pre;
    printf("%lf\n", res);
    pre = res;
  }
  return 0;
}
