#include <bits/stdc++.h>
double const PI = 4 * atan(1.0);
using namespace std;
void OPEN() {
  freopen("A.in", "r", stdin);
  freopen("A.out", "w", stdout);
}
int n;
double a, d, t, v, kq, tg;
int main() {
  scanf("%d %lf %lf", &n, &a, &d);
  tg = 0;
  for (int i = 0; i < n; i++) {
    scanf("%lf %lf", &t, &v);
    if (v * v / 2 / a > d) {
      kq = sqrt(2 * d / a);
    } else
      kq = d / v + v / 2 / a;
    kq += t;
    if (kq < tg) {
      kq = tg;
    }
    printf("%.9lf\n", kq);
    tg = kq;
  }
}
