#include <bits/stdc++.h>
using namespace std;
int n, a, d, t, v;
long double lst, now;
int main() {
  scanf("%d%d%d", &n, &a, &d);
  for (int i = 0; i < n; i++) {
    scanf("%d%d", &t, &v);
    now = t + sqrt((2 * (long double)d) / (long double)a);
    if (now > t + (long double)v / a)
      now = t + (long double)v / (long double)a +
            ((long double)d -
             (long double)v * (long double)v / 2 / (long double)a) /
                (long double)v;
    if (now < lst)
      now = lst;
    else
      lst = now;
    printf("%.8lf\n", (double)now);
  }
}
