#include <bits/stdc++.h>
using namespace std;
int t[100001], v[100001];
double ans[100001];
int main() {
  int n, d, a;
  cin >> n >> a >> d;
  for (int i = 1; i <= n; ++i) cin >> t[i] >> v[i];
  for (int i = 1; i <= n; ++i) {
    double tt = v[i] / (double)a;
    double dist = (double)tt * v[i] / 2.0;
    if (dist >= d)
      ans[i] = sqrt(2 * d / (double)a);
    else
      ans[i] = tt + (d - dist) / (double)v[i];
    ans[i] += t[i];
    if (i > 1 && ans[i] < ans[i - 1]) ans[i] = ans[i - 1];
  }
  for (int i = 1; i <= n; ++i) printf("%.6f\n", ans[i]);
  return 0;
}
