#include <bits/stdc++.h>
using namespace std;
const int MAXN = 100010;
double n, a, d;
int main() {
  cin >> n >> a >> d;
  int x, y;
  double t, p, last;
  for (int i = 0; i < n; ++i) {
    scanf("%d%d", &x, &y);
    t = sqrt(2 * d / a);
    if (a * t >= y) {
      t = y / a;
      p = d - a * t * t / 2;
      t += p / y;
    }
    t += x;
    if (t <= last) t = last;
    printf("%lf\n", t);
    last = t;
  }
  return 0;
}
