#include <bits/stdc++.h>
using namespace std;
int n;
double a, d;
int main() {
  cin >> n;
  cin >> a >> d;
  double pre = -1;
  for (int i = 1; i <= n; i++) {
    double t, v;
    scanf("%lf%lf", &t, &v);
    double time = sqrt(d * 2 / a);
    double ans;
    if (time * a > v) {
      time = v / a;
      double dis = time * v / 2;
      ans = (d - dis) / v + time + t;
    } else {
      ans = time + t;
    }
    if (pre == -1) {
      pre = ans;
    } else {
      pre = max(pre, ans);
      ans = max(ans, pre);
    }
    printf("%.10lf\n", ans);
  }
  return 0;
}
