#include <bits/stdc++.h>
using namespace std;
int n, a, d;
int main() {
  scanf("%d%d%d", &n, &a, &d);
  double anst = 0, anst1, s1;
  for (int i = 0; i < n; i++) {
    int t, v;
    scanf("%d%d", &t, &v);
    s1 = 0.5 * v * v / a;
    if (s1 > d) {
      anst1 = t + sqrt(2.0 * d / a);
      if (anst1 < anst)
        anst1 = anst;
      else
        anst = anst1;
      printf("%.9lf\n", anst1);
    } else {
      anst1 = t + 1.0 * v / a + (d - s1) / v;
      if (anst1 < anst)
        anst1 = anst;
      else
        anst = anst1;
      printf("%.9lf\n", anst1);
    }
  }
  return 0;
}
