#include <bits/stdc++.h>
using namespace std;
int n, a, d;
int main() {
  scanf("%d %d %d", &n, &a, &d);
  double ant = 0.0;
  for (int i = 0; i < n; i++) {
    int t, v;
    scanf("%d %d", &t, &v);
    double mruvt = (double)v / (double)a;
    double distali = (mruvt * mruvt * (double)a) / 2.0;
    if (distali >= d) {
      double tot = t + sqrt((2.0 * (double)d) / (double)a);
      tot = max(tot, ant);
      printf("%.10lf\n", tot);
      ant = tot;
      continue;
    }
    double nd = d - distali;
    double tot = t + mruvt;
    tot += nd / (double)v;
    tot = max(tot, ant);
    printf("%.10lf\n", tot);
    ant = tot;
    continue;
  }
  return 0;
}
