#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  double a, d;
  scanf("%d%lf%lf", &n, &a, &d);
  double t, v, time = 0.0, s, s1, flag = 0.0, x, y, z;
  x = sqrt((2 * d) / a);
  y = sqrt(2 * a * d);
  for (int i = 0; i < n; i++) {
    scanf("%lf%lf", &t, &v);
    x += t;
    if (y >= v) {
      time = v / a;
      s = 0.5 * a * time * time;
      time += t;
      s1 = d - s;
      time += s1 / v;
      flag = max(flag, time);
      printf("%0.6f\n", flag);
    } else {
      flag = max(flag, x);
      printf("%.6f\n", flag);
    }
    x -= t;
  }
  return 0;
}
