#include <bits/stdc++.h>
using namespace std;
int N;
double a, d;
double res = 0;
void scan() {
  scanf("%d%lf%lf", &N, &a, &d);
  for (int i = 0; i < N; ++i) {
    double t, v;
    scanf("%lf%lf", &t, &v);
    double tm = v / a;
    double dist = tm * v / 2.;
    if (dist > d) {
      double tt = sqrt(d * 2. / a) + t;
      tt = res = max(tt, res);
      tm = tt;
    } else {
      double dd = d - dist;
      tm = tm + (dd / v) + t;
      tm = res = max(tm, res);
    }
    printf("%.6f\n", tm);
  }
}
void solve() {}
int main() {
  scan();
  solve();
}
