#include <bits/stdc++.h>
using namespace std;
const int INF = 0x3fffffff, M = (int)(2e3 + 100);
int a, d, n;
int main(void) {
  while (~scanf("%d%d%d", &n, &a, &d)) {
    double pre = double(0);
    while (n--) {
      double anst;
      double x, y;
      scanf("%lf%lf", &x, &y);
      double t = (y / a);
      if (t * y / 2 > d)
        anst = sqrt(2 * d / double(a));
      else {
        anst = t + (d - t * y / 2) / y;
      }
      if (anst + x < pre)
        printf("%.10f\n", pre);
      else {
        pre = anst + x;
        printf("%.10f\n", pre = anst + x);
      }
    }
  }
}
