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