#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, a, d, t, v;
  scanf("%d%d%d", &n, &a, &d);
  double pre = 0;
  double ans, t0;
  for (int i = 0; i < n; i++) {
    scanf("%d%d", &t, &v);
    t0 = v / (double)a;
    if (0.5 * a * t0 * t0 > d)
      ans = sqrt(d * 2.0 / (double)a);
    else
      ans = t0 + (d - 0.5 * a * t0 * t0) / v;
    ans += t;
    if (ans < pre) ans = pre;
    printf("%.10f\n", ans);
    pre = ans;
  }
  return 0;
}
