#include <bits/stdc++.h>
using namespace std;
int n;
double a, d, v, t;
int main() {
  while (cin >> n >> a >> d) {
    double last = 0;
    while (n--) {
      cin >> t >> v;
      double m = v * v / 2 / a, ans;
      if (m < d)
        ans = v / a + (d - m) / v + t;
      else
        ans = sqrt(2 * d / a) + t;
      if (ans < last) ans = last;
      printf("%.10lf\n", ans);
      last = ans;
    }
  }
  return 0;
}
